all other things being equal, a 12" 45rpm pressing will outperform a 33rpm pressing of the same recording. it will have clearly greater bandwidth and dynamic range, show more scale and authority, and have more detail. it will sound bigger and bolder. just the physics of the media.
and normally a 12" 45rpm pressing will be better mastered, since there is more room for wider grooves allowing for more dynamics, and to get paid the premium for the 45rpm process, greater care is typically taken with the whole process, thicker vinyl is typically used.
but there are variables involved, so only about 80% of the time does the 45rpm actually surpass all 33rpm choices. mostly the cases where the 33rpm is equal or better involve original pressings where the source master tape is fresh and optimal care was taken. many of those original pressing cost more to acquire (if you can find them) than the 45rpm versions.
I own most of the 12" 45rpm pressing released in the last 20 years, maybe 1500 titles, most with 2 discs per title. some box sets too. it's been a big part of my vinyl listening.
the most credible knock on 45rpm pressing is that they contain half the music a typical 33rpm pressing have so are more hassle to get up and change and disrupt the listening flow. that is for the individual to decide the priorities.
but there is no dispute that they normally sound quite a bit better.