I moved from a Pi setup to a second hand Lenovo M900 tiny PC, with 24GB of RAM and nvme drive and it works great. The power efficiency is obviously not as good as the Pi but it's a reasonable trade off
Tiny PCs are a good option, too - especially ones based on mobile processors. I just built up a barebone Asus PN50 (Ryzen 7 4700U equipped) and I'm quite impressed at what this little box can do. The 4700U is kind of weird - it has SMT disabled, so it kind of slots between the usual Ryzen 5s and 7s. No matter though - builds on it are quite fast. But it's still x86...