It's been a while since I've purchased any new games, and I was wondering if there are any current games similar to Metal Gear Solid and Splinter Cell (preferably for the PS5 or Nintendo Switch). Any recommendations?

The new 007 James Bond game was very well received. I haven't played it but I'm pretty sure it has a lot of stealth elements to it mixed in with some action segments.

The Hitman series is also doing really well. The most recent game in the series looks & plays really well on PS5 and I'm pretty sure it has a ton of content (either free or add on DLC). This is probably the closest match (that I can think of) to Splinter Cell.

Hitman seems like the most obvious suggestion. World of Assassination is the Hitman 1, 2, and 3 campaigns combined into one

And maybe the Batman Arkham games? I haven't played them, but i know they lean heavily into stealth elements.

Its an older game from 2017, but Tom Clancy's Ghost Recon Wildlands is awesome

If you're down to switch perspectives, the Dishonored games are pretty good for stealth.

the sniper elite games are pretty stealthy, and you can handicap yourself to stealth kills only for the most part.

The Sniper Elite games are good. Play the levels how you like, but I tend to tackle them like a combination of Sam Fisher and Agent 47.