I followed this manga at the very start for 20-30 chapters or something before the anime aired.
Then life and I kinda dropped/forgot about it.
Now I just randomly came across this a couple months ago and on a whim strated reading the latest chapters with no context; and despite that this feels great to read. It genuinely feels better than most of the mainstream shoumen that I have seen in last 3-4 years.
(I actually haven't been following Anime and Manga for a long time, so I maybe very wrongly biased)
I definitely recommend going back to catch up on the chapters you missed, when you get the chance. There was a major story reveal around chapter 100, and also important context behind the last few chapters' fight against Stigma.
Shy has much better writing, and a different vibe from typical shonen action series. I've seen people say it's more like a magical-girls series with a superhero skin. Shy and Dandadan are the only shonen action series I'm following, as I just couldn't stand the writing in other ones I've tried.
(And if you enjoy the watching-timid-girl-grow aspect of Shy, I think you'll likely also enjoy The Demon Girl Next Door/Machikado Mazoku. It's a magical girls slice-of-life comedy, but with a serious, overarching story and mystery.)