Nostalgia, as other have mentioned. But finding a good deck and maintaining it today can be frustrating. Then, finding any new recordings in the format is problematic.
But yeah, they were probably the pinnacle of analog sound reproduction for those who can't afford (or don't want) a ~$8000 vinyl playback system.
For sound quality, I'd *almost* put my Sony 3-head cassette deck with Dolby S and a metal TDK MA-XG tape up against most reel-to-reel running 7.25 IPS.
For those with r-2-r, enjoy them, but I can't see anyone just wanting to "get into it" here and now in 2023. You'd likely get more bang for your bucks by elevating your music streaming system and/or DAC, room treatment, or speakers.
Then you do have the issue (just like all the studios and record labels) that magnetic media will deteriorate over time, indeed, each time they are played, just a bit.
Ah, but man, watching those large spools of tape going round and round is addictive I'm sure. My brother-in-law had a very nice r-2-r set up in the 1970s but it was stolen. It was mesmerizing and yeah, sounded great in its day.