Traveller's setting, wonderfully 1970s vision of futuristic technology, etc., and everything else is great, and its character creation is a beloved RPG meme for a reason.
The gameplay loop, though, is what made my players nope out.
Character improvement is almost non-existent, which makes sense, given that character generation tells the story of a character's life over decades. Instead, it's about improving characters' circumstances and, typically, their ship or their career.
In other words, your friends can get together with you and roleplay the far future fun of paying a mortgage (on a spaceship, but still), running a small business (a trader flying between worlds) or trying to succeed in their career (aboard a space-going naval vessel). My players, who already spend enough time worrying about this stuff as adults, said no thank you, and wanted to go back to heroic fantasy.
I think Traveller is a very fun document to own and read and I know many people enjoy it today, but I would probably run a game of Scum & Villainy instead, which has a much more satisfying narrative loop in each of its three modes.