I should disclose first that making a 12" at 45 rpm takes the LP feature away, which I don't care for. More importantly, all else equal the faster the speed the more noise will be generated. This can be significant for the stylus tracing the record groove. Everything is a trade off. Some of the gains are offset by the loss due to the inferior signal to noise ratio. The extra vinyl muffin costs pennies and it is actually easier to master at the higher speed so it takes less studio time in most cases. Time is money.
On balance it is a marketing ploy to pry more money out of the consumer for a more profitable product. Sometimes 45 rpm records sound better, but not always.
Do 45 rpm 12" LPs really sound better than 33 rpm?
Increasingly, one can buy 12-inch 45 rpm LPs. Theoretically, they provide a wider dynamic and frequency range, but I come across a strange effect... Yes, the bass strings seem to be tightened stronger, but in general ... Imagine you have two cars with a power of 250 hp, but one is equipped with an honest atmospheric V6 or V8, and the second has 2 liters turbo.
Tell me, is it just my impression? Or maybe I need to change the cartridge or settings (for example, impedance) of the phono preamp?