T.M. HDD - USB vs. powered? Pros & Cons

I recently bought a Mac Studio M4 Max & Apple Studio Display to replace my late 2015 27” iMac.

Since my Studio SSD is 1 TB I want to have a 2 TB external HDD for T.M. Purchased in 2016 so, ~ 9 years old.

(Actually I will get 2 & have them alternate hourly backups, as I do now)

My current backups are Seagate STEB5000100, 5TB, whIch are powered so use AC power cord + the USB connection.

I have searched this forum & more. The general consensus seems to be that using an SSD is pretty much a waste of money for Time Machine backups & there also may be some other disadvantages for this particular use.

So I am shopping for HDD and a lot of people recommend your backup s/b 2x the capacity of your Mac HD. So I am looking at 2 TB HDDs.

I like the idea of a HDD that is USB powered & prefer USB-C rather than USB 3.0 + an adapter to use in my Mac studio USB-C ports.

But, I wonder if the HDDs that are externally powered have some advantage.

I plug all AC power cords into a CyberPower UPS (CP 1500 AVR LCD) so not having to power the HDDs externally would free up power slots.

My UPS has 12 but only 6 are battery backup slots.

I also am seeing some enclosures where you must buy that + buy a separate HDD to snap into place inside. I would not know which specific HDD to pair with an enclosure or why that would be better than buying an all in one HDD.

I do not use my Mac professionally, like a video editor or professional photographer who has need of much more storage capacity than I do.

Advice appreciated.

Thanks!