Admittedly any 4k title I get is always BR+4k because I’m hedging my bets about a future 4k upgrade. I have a very hit-and-miss BR player which will be replaced at some point and it’ll only be logical to get a 4k player at that point, and the TV will need replacing some day too.
I used to think that too, believing that my DVDs were “good enough” quality, then when I later downloaded movies that were ripped from say BR format, I realised the level of detail upgrade involved. I started seeing BRs for bargain bucket prices and decided to take the plunge because it’s quite a difference when watching on my desktop PC screen for example.