I remember reading them back in the early 90s (Robin Hood: Prince of Thieves, Far and Away, Back to the Future). They don’t seem to be a thing anymore (or am I just not noticing them).
As an aside I remember liking them but I was a preteen at the time so maybe they were terrible and I just liked the movies.
Tarantino wrote one for Once Upon a Time in Hollywood, although that was an intentional nostalgic throwback to the heyday of novelisations.
I remember as a kid I had a novelisation of Jurassic Park. Not the book that movie was based on, but a novelisation of the actual movie. I remember liking it quite a bit.
The Doctor Who novelisations are famously good, and for many fans of the original (Classic) run of the show, the novelisations are more memorable than the show itself. Any of the ones written by Terrence Dicks are especially good.
The novelisations of the Star Wars prequels are better than the movies, especially Revenge of the Sith. They take the great ideas George Lucas had in that trilogy and iron out the stilted execution.
They’re from an era when movies weren’t available on demand. It was harder to find a movie again after it left theatres, so novelisations filled the gap. They’re still around, but far less necessary than they used to be.