Slow at starting up and loading all of its assets

When you say “latest version of Lightroom”, what is the exact version number? 

Once I upgraded to Lightroom Classic Version 15.4 and 15.4.1, I am seeing noticeably faster catalog loading times on startup. After that, all other functions work just fine. My catalog is on a 2TB Samsung NVME drive that is separate from my system drive. See my specs in my signature. 

I have a MacBook Pro M1 Max for travel. With a really high end PC, I don’t think a Mac would be that superior, but the latest versions of Mac M4 and M5 do have some very high performance especially the high end Studio versions. 

I have been using LrC for many years on several different versions of Windows, none of which have been stellar performers.  After watching a lot of training videos on YouTube, and following the progression of Lightroom through the years, I have come to the conclusion that if you want a computer that you can really count on performing the way you would like you need to consider switching to some sort of Mac.  That seems to be where the emphasis is being placed.  New features for speeding things up, such as noise reduction, are geared to take advantage of Apple silicon.  Windows users will not benefit from many of the "speed benefits".  Just watch a YouTube tutorial given on a Mac.  For instance, my Windows computer will take five minutes to complete noise reduction on a very small, 21 megapixel, raw file.  The tutorials usually show the same task being completed in about less than 10 seconds.  But I am 83 now, so it's hard to justify making a change.  I just ramble on with my old slow Windows computer.