Is it worth the money to buy an SSD with 2000MB/s Read/Write for my 2019 Macbook pro16?

Macs do not support USB 3.2 Gen 2x2 ("up to 20 Gbps / 2500 MBps").

If you connect a USB 3.2 Gen 2x2 drive to a Mac, communication will fall back to a slower speed that both the drive and the Mac can support. Typically

• USB 3.1 Gen 2 ("up to 10 Gbps / 1250 MBps") for a USB-C host port
• USB 3.0 ("up to 5 Gbps / 625 MBps") for a USB-A host port

IMHO, a USB 3.1 Gen 2 SSD is plenty fast enough for backups, and for storing things like your music, movie, and TV show libraries. If you need a really fast drive because you are doing things like constantly working with 4K/8K video for a living, then the next step up would be a Thunderbolt 3 SSD. But those are more expensive and the speed may cause them to run hotter.

For Time Machine backups, I use the Crucial X8 (1050 MB/s) on two Macs, and for my Mac Mini M2 Pro, I use a new Crucial X9 (also 1050 MB/s). I didn't need the synchronous 1050 MB/s performance and extra cost of the X9 Pro for the Time machine solution.

I use the USB-C 3.2 Gen 2 (10 Mbps) cable that comes with these drives and connect it directly to a USB-C port. On my 2020 iMac, that USB-C cable is plugged directly into the TB3 port.

With these Crucial drives, Time Machine backups happen so quickly that you are unaware that they happen except for an operating system upgrade (e.g. Sequoia) and a new TM drive backup. You would be wasting your money on a 2000 MB/s SSD.

For Time machine, a drive 2 to 3 times or larger than your boot drive is preferable for long term trouble-free operation. Do not pay extra for a drive that is fast.  

Time machine works quietly and automatically in the background, without interrupting your regular work. It gets no benefit from a drive that is FAST.

IMO, for incremental backups (e.g., Time Machine), no…at least, my 4 TB Samsung T7 SSDs are quite fast at 1050.

Errata: I misstated USB 3.2 Gen 2 (10Mbps). It should be 10 Gbps.

You are welcome.