I don't really have anything to add but I also recently spun up a Sinatra app for my personal use and I really had a lot of fun doing it. It was my first time using Ruby since 2022 when I left a Rails job, after having spent more than the previous decade primarily writing Ruby. I love the language and community so much but I don't have a professional use-case for it at my employer today, and I don't have a lot of free time in my personal life, so I just don't end up using it much. Thanks for sharing your thoughts here, I resonate with them a lot!