USB-C SSD Hotswap docks are as fast as SATA but with slightly slower write speeds but way faster read speeds.

I find the hotswap docks light years faster than external towers because external towers often use weaker SSD's, usually "ECO" versions which are the slowest style around but cheaper for the company.

I remember people buying the WD External Towers for $90 on sale, cracking open those towers to pull out the 3 WD Green label (weakest drives from WD) SSD's to resell individually.

It is not USB2/3/4, those all suck, USB-C and of course anything Thunder is far better but Thunder will still be limited to how fast the internals are based.

People use Thunder for external GPU solutions on laptops.

You can think of Thunderbolt like an external PCIe interface so an external NVMe SSD using Thunderbolt is going to be pretty much akin to installing a PCIe NVMe SSD internally like your existing SSD (assuming it's NVMe).

Thunderbolt can also run the USB protocol over it.

Thunderbolt 3 supports up to 40Gb/s
USB 3.2 Gen2 (2x2) uses 2x 10Gb/s lanes and can support up to 20Gb/s; but not as a single transfer.
USB 3.2 Gen2 supports 10Gb/s
USB 3.2 Gen1 supports 5Gb/s
USB 3.1 Gen2 supports 2x 5Gb/s lanes similar to 3.2 Gen2 (2x2)

Going back to USB 2 speeds is significantly lower at 480Mb/s.

So it depends on the disk you're looking at.

A decent USB 3.2 SSD is going to be perfectly fine for running Steam games from without issue; although some games may have specific requirements in regards to disk IO that could be a limiting factor. Regardless, most games do not need a super high performance disk and are mostly influenced by the disks IOPS and read speeds.

Copying games to/from the external disk to/from your internal SSD will however benefit from the faster throughput so it being "worth it" or not is really somewhat up to your usage behaviors.

Thank you, guys, for your replies.

I must confess, a lot of what you said sounds like Greek to me 😄

So, if I understood correctly, there's really no need to spend a lot of money on a Thunderbolt SSD for gaming, right? Any USB SSD should work fine, as long as it's USB 3.0 or higher (preferably 3.2 Gen 2)?

Also, I checked the Device Manager on my laptop, and it seems all the USB ports are 3.1. Does that mean only USB 3.1 SSDs will run at the highest speed on my laptop? Or can I plug in a USB 3.2 or even USB 4.0 drive into the Thunderbolt port and still get the maximum speed?

Sorry for all the questions - I've done my research, but I still have a lot of doubts, and I really don't want to spend a bunch of money on a device that ends up being useless to me 😅

As for the possibility of changing the internal drive, just Google "change HDD in [insert brand and model of laptop here], look at some of the results and decide whether you can attempt it.

same situation, my budget HP Victus also has a 500gb nvme, got a budget 2tb sata SSD for $85 and a usb 3.2 enclosure for $10, works flawlessly.