Yea essentially they are two methods of achieving similar results: breaking the on chain connection between your original UTXO and your resulting UTXO. It doesn't erase the record of purchases on a KYC'd exchange, but it can obfuscate where those sats went and who owns them after they were withdrawn. Reasons to care about doing this will differ depending on where a person is from (legal jurisdiction), what they're intending to use the sats for, etc. There are other methods too, like such as utilizing Liquid. As to why a person may choose one method over another, it may just be what they've been told to do by their friends, or the only method they know of. I'm sure on some very technical level there may be pros and cons to each.