Back up storage solutions

[paul10]

I have a existing wd duo 20tb in raid configuration back up / redundancy but it is real slow in disk speed test especially when migrating large files in mass i am currently updating my lightroom catalogue as i have a new pc ,which is painful meaning i have to import on to drive basically having two copies of each image until i delete the old the version remind me never loose lightroom catlogues or delete them all ,not really knowing the best way to save my images or how catalouge correctly some people have multiple catalogues ,i have purchased a das qnap tn-02 hoping this will improve things for faster read and writes over my existing wd duo ,i also purchased a iron wolf pro 16tb hoping to get a second one that iwas going to install on the qnap but i might change this as synology are getting bad press at moment with used sales of hard drives used on crypto farms etc although i think this is more exos range ,so what i am really asking is sata iii always going to be my bottle neck wth read write on das drives with mechanical drives even if transfer rates are greater now with thunderbolt and usb 4.0 etc .Is it worth getting a owc back up soloution or gtech or lacie if i am only buying mechanical drives is ssd3 always going to be the bottle the neck with read writes .Any info much appreciated