I used solargraph for a really long time and it mostly suited all my needs, but I've seen it chew through memory in resource-bound environments (laptops with > 8GB RAM). Solargraph is very mature and is actively developed as of today. I'd say it's still a very fine choice for anyone needing some LSP features in a text editor.
Personally, I switched to ruby-lsp some time back and haven't needed anything else but my requirements aren't the norm. I spend a lot of time in a terminal with tmux, vim/helix (which has ootb support for solargraph
), and a handful of monitoring tools.
Overall, I would say solargraph should fit the bill for most users. Ruby-LSP is great if solargraph isn't cutting it for you in some way.