I didn't grow up with the PC Engine or TurboGrafx, but I did start getting into it after I got the MiSTer.
I find that the unsuccessful [1] consoles are generally pretty bad. The 3DO and the Jaguar and CD-i are mostly pretty crappy, and while it can be fun to play for a novelty and you might even find one or two games that make it worth it, the vast majority of the time there's a reason that people don't seriously revisit these consoles. To be clear, I did grow up with a 3DO and Jaguar (well, I got both when I was thirteen), so I'm not speaking out of my ass here.
So I was actually very surprised that the TurboGrafx games were actually quite good. Like, I kept going through random games, and I was shocked to find that a lot of them were actually very well made; decent graphics, tight controls, and fun gameplay.
There are terrible games on there, but I was kind of shocked to find that they appear to be outliers.
Now I kind of wish I had grown up with the Turbografx.
[1] A relative term, I acknowledge
I wouldn't call the PC Engine unsuccessful. Sure it did poorly in the US, but it did well in Japan, even outsold the Mega Drive (Genesis). That's definitely part of the reason it had quite a few good games by Japanese companies.
The Jaguar catalog was mostly meh, but there were a few gems that I really enjoyed (Aliens vs Predator, Doom, Wolf 3d, Iron Soldier, and Tempest 2000). AvP alone was worth the price of the system.
I was a proud Turbo DUO owner. It had some fantastic multiplayer games, especially 5-player Bomberman. That got a lot of play, including tournaments at work. Dungeon Explorer is another one we played through multiple times.
Maybe they should have sold the TurboGrafx-16 in the US only with the CD add-on already built in, and one or two CD games included to set off the hardware price somewhat. That would have made them stand out versus SNES/Genesis.
Tons of the games were simple shmups, so I can understand people who might have the wrong idea about the library. Also, the library in Japan was way more impressive than what made it to the west. Gekisha Boy in particular still stands out as a fun and unique game (though you can play a translated version on your Mister). Fire Pro 3 is an incredible wrestling game that I still play today (no japanese required). There was another game, Zero4 Champ, which had unique drag racing gameplay (it was all about timing your gear shifts). It was hard to play without japanese knowledge, except for the 2 player head to head races. For CD games, of course, Castlevania: Rondo of Blood is well known.
I always thought the 3DO was good hardware, for 1993, let down by a high price (especially by 1993 standards) and a poor library of games: there just wasn’t a good incentive to buy the thing.
Fast forward a couple of years and the PlayStation and Saturn are both out, more technically capable, cheaper, and with better game libraries.
However, I really do think the main thing that killed the 3DO was the price - it was wildly and ridiculously expensive compared with the alternatives - and the lack of games sort of followed naturally from that because who’s going to develop for a console hardly anyone bought?
The inter-generation timing of its launch probably didn’t help. Who’s forking over when you know Sega, Nintendo and - it turns out - Sony are all going to release something better in a year or two?