Absolutely, someone will as long as someone wants to, even with mastodon (apparently!) 😀

But my intuition has always been that requiring less complexity and thus simpler hardware/software is better for decentralization, and resilience in general.
(same advocating for a relatively simple PoW algorithm, if it doesn't require Intel's full design expertise to design and build, it ought to be harder to fully capture it)

Another good side of "simple servers, complex clients" in this case is that iteration and experimentation is much easier, not everything has to be coordinated with whoever runs the servers. Seeing this on mastodon where people are still having energetic discussions about "should we support quote-tweets" 6 years after it first came up 😨