And don’t forget about the multiclassing and spells all around to further handle “thief-like” needs. Invisibility, silence, fly, spells as rituals not using resources (except time), etc.
I remember (“Back in my day…”) the thief character was the one who scouted ahead of the party to scope out the room, listen at the door, check for and pick locks, check for and remove traps, etc. Many of these things are either less prevalent, less dangerous, or some combination of the above. “Perception” and “Stealth” are available, the aforementioned spells, bard flexibility, multiclassing, etc. all can eat into that niche. Which, don’t get me wrong, is okay, because then you don’t need a thief in the party, but it feels like all the classes are becoming “samey” and focused mostly on the combat elements, and not the “out of adventure” elements.
We would usually encounter things going on in the towns and cities we returned to to spend out coin, which resulted in adventures in the city, which required the thief to climb to upper stories, slip into windows, hide in people’s great halls, etc. so the party could access the site, or sneak in, or whatever. Now we just “misty step” somewhere. It might not be a “heist”, but it required sneaking around the town, and the party followed where the thief scouted the “safe” route. Not so much nowadays.
