Changing your power amplifier can improve your system, but as the saying goes, “it all depends.” I changed from a highly-rated tube amp to Odyssey Kismet solid state monobloc amps that are twice as powerful as the stereo tube amp. The change was dramatic and instantly noticeable. It depends, however, on your preferences and the specific characteristics of the power amplifier involved. My earlier change from a highly-rated solid state amplifier to the tub amplifier did not sound as well, hence the switch back to a solid state power amp with my Rogue Audio tube preamplifier.
Let your ears be the judge, but there is very good counsel be had in this forum.