Comparing a Yamaha s301bl to a rega elicit mk5 - a/b on some paradigm 800fs and they sound the exact same. Looking at the specs it makes sense - I don’t know why I’d ever use the full wattage of even the Yamaha without getting hearing damage and the THD being 0.019% vs 0.004% makes no functional difference. Are high end amps the new snake oil? What exactly are you getting for 10x the price here (besides the rega having less features and the rega brand name?)
I upgraded from my pair of IOTAVX pa3’s to a pair a VTV Purifi monoblocks and when I was A/Bing them, they were very very close to sounding the same. The only thing that stood out is the IOTAs had a lot more bass. There were little differences here and there in the rest of the frequency spectrum but you reeeealy had to listen for those tiny differences. Once I stopped A/Bing them and just listened to the Purifi’s, there are a few things that don’t seem so similar anymore. The Purifi’s sound like they have full control over my speakers top to bottom and even when pushing the speakers really hard. Nothing loses composure. The treble sounds more refined, bass is tighter, more detailed, and faster. I thought the same as you when I was A/Bing them. My advice is stop A/Bing and listen to one for a few weeks, then listen to the other one for a few weeks.