It's true but not realistic as soon as the website is more than a blog or a static content website. The goal of good web building is to manage to deliver the most value to consumers and the business, and removing what's not needed, and if you add anything, you make it on a performance oriented way. Bloat will always infiltrates itself, so you must clean again and again. I operate e-commerce websites and we went through multiple iterations with two goals in minds : performance ( speed / core vitals / seo ), and developer productivity (I'm basically the only tech guy, and I'm also the CEO managing 10 people). Our current e-commerce stack runs 99% on Phoenix Live view. As our market is only in 1 country (Philippines) we optimize for round trip network with servers the closest possible ( no decent hosting company in the country so we host in HK at datapacket on a beefy dedicated ). Site loads in less than a second, navigation is nearly immediate thanks to live view. We removed most JS trackers as we built our own server side tracking pipeline in Elixir that sends unified data where it's needed ( it took us like 2 days to build ). Since that move Google loves us and we are the top ranking website for our niche in the country on all our key products.
One key thing also is that our target market is wealthy so they enjoy fast data / connection, this helps in terms of determining our target.
Performance is not absolute. It's relative to your product, your market and your location.
Hell, my blog is static HTML (mostly) but my most recent post is 40,000 characters in Markdown before adding HTML tags, that's already too big even just as text.
Nice site. I am also in a similar position, now rewriting our website to make it modern and fast. Like your site that its snappy, but found something odd.