Might be a nitpick, but there’s also the problem of what exactly we are calling a “serious commercial project”.
Right now the most successful game made with Godot Engine is Cruelty Squad (https://store.steampowered.com/app/1388770/Cruelty_Squad/). Regardless of if you would call it “professional” or not, it was one of the most noted indie games of 2021, had great reviews, and probably was much more commercially successful than your average Unity/Unreal “professional” indie title (given how so many of them flop). Same goes for some highly successful RPG Maker games, which usually people would not call it a “commercial-quality” engine.
I think there’s a lesson here: don’t care that much if you’re using a “commercial” quality engine or not, just care if the engine will give the right tools to make the game that you envision.
There are still people out there rolling their own engines for commercial projects, it's all about what you can pull off with the tools you've chosen. But I would agree that there's a professional network and support system around Unity that Godot currently doesn't have. If you're planning to hire a team, it'd be much easier to find good Unity developers than Godot devs.
Some of the most egregious issues turned out to be because people on Twitter were not disclosing that they were running a brand new Switch game in an emulator.
But even aside from that, I'd argue Godot probably had little to do with the quality of the port. There's ample evidence that you can make buggy games with any engine, and the Sonic franchise in particular seems to have a long running problem with SEGA pushing releases out half-baked.
Right now the most successful game made with Godot Engine is Cruelty Squad (https://store.steampowered.com/app/1388770/Cruelty_Squad/). Regardless of if you would call it “professional” or not, it was one of the most noted indie games of 2021, had great reviews, and probably was much more commercially successful than your average Unity/Unreal “professional” indie title (given how so many of them flop). Same goes for some highly successful RPG Maker games, which usually people would not call it a “commercial-quality” engine.
I think there’s a lesson here: don’t care that much if you’re using a “commercial” quality engine or not, just care if the engine will give the right tools to make the game that you envision.