Why do people choose SSDs when they know SSDs have a TBW limit?

 This is the same reason why people buy HDDs knowing that they have a specific, documented MTBF. We all need mass storage in our computer.

Both types are not perfect, but by 2022 an SSD will last longer than the average user HDD, which is 50 times faster, and prices are lower, and are likely to upgrade more capacity than you might see in 3-6 years. 

The major SSD drawback is that it has limited writing cycles. So, anything that uses that quota unnecessarily, is an integer.

The SSD uses a small amount of RAM

If you're the kind of person who keeps lots of open browser tabs, apps running in the background, photo editing, video editing, and virtual machines, your system will use your SSD to prevent your apps from crashing when RAM is full. So, it takes up a part of the RAM and burns it completely to your disk. As you continue to change apps, your OS memory will continue to swap pages and overwrite your SSD, thus shortening its lifespan.

Modern SSDs usually have a ware leveling feature that extends its lifespan. It does this by moving some data and keeping a record of which cell was overwritten. When moving files, it requires empty cells to function as a cache. If you do not have a spare room, the same cells will be used again and again and it will fail faster than expected.

On SSDs there is no need of defragmenting. All data is instantly accessible and you do not have to wait for the plate to spin again to reach the next second of the song you are listening to. Therefore, collecting data together will waste those writing cycles without increasing performance.