So, its probably important to separate Colours HD and Sonic issues in general. Why? Because Sega ports/remakes/remasters being bad is NOT a Sonic only thing, so I feel that's contorting any conversation here.
So Colours HD seems like a rushed port that has its share of glitches, seizure inducing bugs (that's really fucking bad), and just generally being an ill thought out game in so many ways (remixing music that's worse, graphical changes that in some ways look worse than the original, basically everything about the Switch version - especially load times and performance being half what it should be).
But do you remember a few years back? A glitchy game with tons of audio issues was remastered by a team using a Sega IP that only featured Sonic as a capsule toy? Shenmue 1&2 HD. It was rushed, it was outsourced to a team that didn't have enough time, at one point were trying to make similar questionable looking graphical changes like Colours got, and ultimately is only a great remaster if you play on PC with many a mod installed.
How about a more recent example. Panzer Dragoon got a remake that basically released half finished. Bad controls, bad frame rate and again graphical changes that didnt fit the spirit of the original. It was patched to fix the first two issues at least but still...
Remember Alex Kidd? He got a remaster?remake? this year, and the outsourced team who worked on it decided that using the 50Hz Euro version of the game as the template would be a good idea. The game is a juddery mess as it doesnt run correctly at 60FPS. Another own goal with a Sega IP.
And now to RGG/Yakuza... even a good series is harmed by Sega's bizarre curse of not remastering games correctly. Kiwami 2's graphical changes are in some instances weird (Kiryu looking the wrong age), Takashima being aged up a good 30 years because face actor... Cutting content left and right... People want to complain about remixed soundtracks in colours? Try checking Kiwami 2's soundtrack which cut a shit ton of tracks and didnt replace them with better tracks, ESPECIALLY key scenes in the story that had SiM music shoehorned into it.
And the remasters of 3-5? Glitches here and there... Bowling, Pool, Fishing, combat, I dont have the interest to list everything and depending on the port you play (console or PC) you get treated to different glitches there as well.
Judge Eyes remaster and Yakuza Like a Dragon? They felt the need to change the colour tone to the game world and Im still not sure if I like the cool blue over the warm orange look. Then you have mini games getting cut, and for both JE and RGG7 - Space Harrier was not ported correctly so its capped running in mid 50FPS, not 60FPS so its nowhere near as smooth.
Fairly certain the SMT3 HD port had issues as well, but Im not all that familiar with the series so wont comment.
At least Monster World 4's recent console port was rather delightful.
So yeah - certainly not saying Sonic hasnt had its ups and downs as a series lately (I played Forces, I didnt like Forces) but Unleashed, original Colours (emulated with the 60FPS code is a joyous experience), Generations, Mania etc. are all great games that I loved (some more than others) but this one I'm not putting at the feet of the franchise, I'm blaming Sega and the port team who worked on the game - lack of budget, time, bizarre choices (such as using Godot to remake the game from scratch) are all potential issues, but people just saying "lol Sonic" are missing just how bad Sega is with its properties sometimes when it comes to remasters, ports and remakes. Lets see how the Monkey Ball remakes do next month, Im optimistic based on what is shown though I still want to be absolutely sure the physics arent fucked up.
