I think there are a ton of very well-spoken arguments for why everyone, yes even those who "do nothing wrong," should care about privacy, and I would encourage you to look at those. Mostly because the people who publicly speak about this are much more eloquent than I, and have thought much more on the topic.
That said, I think it boils down to this: we all want privacy, but digital privacy is a hard problem because we are not "wired" to understand it. Humans are not good at interacting with systems with perfect memory, huge computational power, and extremely insightful statistical modeling capabilities.
This affects us differently than interacting with a person. Now, a machine can categorize you automatically based on political beliefs, religious beliefs, friend networks, conversational style, etc. This can be used to target you for (arguably unethical) influence via surgically targeted propaganda, or to retroactively mark you as a dissident in a tyrannical regime based on a comment you made off-hand years before the regime took power.
Left unchecked, these invasive tracking systems could be used for a myriad of unethical purposes. And even if you "do nothing wrong," it's important to remember that in most legal systems, it's very difficult to lead a normal life and never break any laws. Add to that the very, very long records these systems are capable of keeping on you, and I think it's clear why many people, myself included, wish to minimize our presence on platforms such as Google.
I think it’s worth while, even just to prevent our privacy from continuing to erode.
Also, who knows what changes in the future? Maybe something you do online today seems harmless but gets you in trouble in 20+ years.
Some people do have things they want to keep private. If only those people care about privacy, then they eventually stick out like a sore thumb and that’s not fair. It’s not always bad or malicious. Diseases, traumatic experiences, conditions, things you should be able to get help with or information on without Google or some other company profiling you.
Who decides if you do nothing wrong? Think about that seriously - who decides what is right and wrong?
Also - if those 'powers that be' decide you have done nothing wrong now, what about in perpetuity? What if in 5 or 20 years who or what you are itself is simply deemed wrong?
These arguments aren't fictional. Being gay and Jewish are just two unchangeable traits that have seen persecution in living memory. Let alone countless others.
Perhaps the Rohingya would be a very recent example.
Be cautious that your own sense of 'right and wrong' in the here and now doesn't cloud the reality that you are beholden to those with actual power to agree with your behaviours and traits - and that those powers can (and will) change over time.
Would you feel comfortable posting your last 100 searches here? What about on a list next to your front door?
Even though you are "not doing anything wrong", perhaps you did a search on that funny looking rash you noticed the other day, or that trivial programming question you needed to look up the answer to.
For me, it is about keeping control of my information. And the best way to control it, is for it not to be collected.
You might want to search for a new job without it influencing searches that may be visible to a current employer.
You may want to search for health topics without it becoming associated at life insurers on the ad network.
You may want your teens to be able to search bullying and sexuality without Facebook or Google tagging those to their profiles, in perpetuity, or worse advertising and retargeting the topics to them.
For me it's mostly that the ads are getting too good. Like, I look at raincoats on some site, then that site's raincoat ads follow me around for the next two weeks. I'm trying to be frugal and not buy more stuff that I don't need, but the ads actually get to me after a while. Adblock helps, but sometimes I have to turn it off for my work (web development).
I find this to be the most compelling argument, because it cleanly positions privacy advocacy as a charitable rather than selfish act.
I believe that individual privacy as a social norm is a prerequisite to free speech, that free speech is a prerequisite to democracy, and that democracy is a prerequisite to fairness in the world.
Advocating for your own privacy is worthwhile if only to provide herd immunity for others less privileged than you, and to send a message about how you wish others would act; to demonstrate popular demand, and to lead by example.
Google has no business keeping a record of each and every one of your searches, tied to your account, but they do it anyway, and they are increasing the tracking by combining the gmail and browser login.
You may start searching for divorce lawyers at some point, and your spouse might stumble upon that.
These search histories could also be obtained with a subpoena, for reasons totally unrelated to you.
Chrome can no longer be safely used to login to google sites. Just because you don't care about privacy now doesn't mean that you won't later.
Do you lock your doors at night? Use curtains or shades on your windows?
Even if you do nothing wrong, would allow streaming cameras and hot mics in your house? How about leaving the door open to allow anyone on Earth to freely enter/exit your property?
Would you want an advertiser to recommend your porn to your love interests? Coworkers? "Popular in your social circle: bukkake MILFs!" We're not quite there yet, but we're close.
Should I switch if I do nothing wrong? I stopped downloading illegal videos and my porn is tame.
What bad things can google do to me if I'm a user that doesnt care about privacy for myself?