Is canon rf a good system to buy into?

Here is what the site says about that.

From Canon EOS R: Canon EOS R: A mirrorless camera by Canon with a 30.3-megapixel full frame sensor, announced in 2018. Canon's first full-frame mirrorless body, now a common used buy.

From Canon EOS 5D Mark IV: Canon EOS 5D Mark IV: A DSLR by Canon with a 30.4-megapixel full frame sensor, announced in 2016. A workhorse, and a good used buy for anyone who already owns EF lenses.

Quoted from this site's pages.