Why would I buy the same three year old camera I already own instead of new technology that will make my job easier every day? and "pay my rent" is a phrase that means "work". Can you do your job without a computer - or if your a ditch digger a shovel? If your a painter you don't buy garbage brushes. Get a clue hobbyist.
Did you get many complaints about your work with the old camera? Do you feel the only way to compete, to keep paying your rent, is to have the newest tech?
Do you imagine that with a camera
better than the 5DIV your work will suddenly be so far above that of other photographers in your area that you will be in high demand? But what happens when they too get a better camera--one as good as yours or even a little better? Tough cycle to keep up with!
Personally, I've found that most good pro-photographers have a pretty high level of craft, and what distinguishes one from another, and what is most important in determining financial success is....wait for it...PEOPLE SKILLS.
EDIT: Full disclosure here. I took a lot of good shots, maybe even a few great portraits, with my 5DIV. Loved it! But once I tried the R and saw the in-focus keeper rate with even f/1.2, and saw how easy it made avoiding dumb exposure errors, I was hooked. So, yes, the R just made my job easier. In fact, just recently, I started finally using the eye AF for portraits! Wow! Now my composition has begun to improve significantly too! I just let the camera keep the eye in focus, and I don't have to be jerking the camera trying to move the AF point or move the body itself. So, I see where you are coming from in WANTING something better--because it helps a lot. But there are alternatives. I think an R is a fine second body to have with the R5, but time will tell. The R does make life much easier! BUT IT DOESN'T PRODUCE NOTICEABLY BETTER IMAGES THAN A 5DIV USED CORRECTLY. And of course it has some weaknesses with fast action.