The people tasked with creating 2015 either sucked or had no budget
If you stop watching the actors and look at the set design, it’s really on the cheap.
There’s a few great ideas like flying cars, self drying jackets, self lacing shoes, etc, but they can only take you so far.
Example, the cars in the future are 80s concept cars and as such, look like 1980s cars. Some were just weird cars used in other movies that they had laying around the backlot.
Then there’s Marty’s neighbourhood, they have cheap coloured lights just sitting on the kerb. No attempt is made to make it look like the kerb. That’s a set done on the cheap.
Now Marty’s house. The interior is very 1980s. Surely they could have hired someone with an imagination who could have decked that place out.
I get that he’s not a rock star and the house may be old but the movie would have benefitted from continuing the ultra futuristic 2015 presentation with flying cars.