I think the one-year personal license is priced very competitively just considering the current feature set. But in the last ~2 years (since I've been an active user) there were a very good amount of updates - between amazing new features (3D stuff for example), time saving QoL updates and a ton of fixes and performance improvements it would be quite unfair to say that the subscription is overpriced.
That said, if you're looking for something conceptually similar to Construct 3 for free, you should check out GDevelop (which is also open source). It's years behind C3 feature-wise but I've tried it a couple of months ago and it's quite nice.