This deck without the YC stamp would probably not be sufficient for serious investors for a variety of reasons: Missing market size, addressable market, and market growth, doesn't answer the question of "why now"? (whereas why this and why you is answered). It isn't a bad deck but let's be honest here.
If you have to convince VCs about market size for early stage investment (seed, A), you likely are talking to the wrong people.
VCs who will fund you already agree there's a potential market and are willing to make a speculative bet based on patterns like data + open source that have worked in other investments. Market numbers tend to be more or less imaginary at this point.
The pitch deck first and foremost tells a story with the objective to get a VC interested - or not. This is a necessary but not a sufficient step in the process. Think of it as a marketing prospectus or a 'door opener' type of thing.
If a VC is indeed interested they will conduct intensive due diligence and leave no stone unturned.
In our case, we're disrupting a well-known industry. So only a non-educated investor would ask for the total addressable market, and the "why now". Both are pretty obvious if you know the industry.
Having investors ask us about those was a strong signal that those VCs didn't know enough about our market, so they wouldn't be great partners for you.
However, in a standard pitch, I would agree those slides need to be there, especially if you're creating a new category. On our side, we're disrupting a well-known one, so not the same.
That's completely my experience as well. At this stage you need investors who understand the market. (Congrats by the way on getting Accel to pony up!)
> Think of it as a marketing prospectus or a 'door opener' type of thing.
YC and other accelerators help to get in the door though. My first deck was worse than this but we ended up with USV at seed (thanks to the accelerator, in my opinion), which opened the doors through B/C and out.
This deck without the YC stamp would probably not be sufficient for serious investors for a variety of reasons: Missing market size, addressable market, and market growth, doesn't answer the question of "why now"? (whereas why this and why you is answered). It isn't a bad deck but let's be honest here.