That will depend on what your project requires. There are a large number of Pi users that could get by with a simple x86 desktop-class PC or thin client [1] which, as the article points out, can have pretty similar wattage and compute power compared to say running 3-4 Pis.
It gets a little tricky when you start talking about GPIO requirements. There are things like the ASUS tinkerboard [2] but it's much more expensive than a Pi.
[1] https://arstechnica.com/gadgets/2022/11/used-thin-client-pcs...