I struggle to understand these arguments about file size. A 128 Gb CFx card will hold about 2,800 RAWs and the cost of hard drives goes down every day. The one time you need to crop in and save a picture is worth it. You don't take an Instamatic to a wedding because you seldom need high resolution but you take a high-end camera because it minimizes the number of times you have to say I'm sorry that your first kiss was fuzzy because I lost track of time and was in the back of the church when it happened! The reason professional photographers buy the best is that you prepare for every eventuality that you can so if your 45Mp sensor saves your behind once, it's worth it and all the wasted file space is forgotten.
It's has nothing to do with storage and space and everything to do with processing power. I have modern i7s in my laptops and a Ryzen 7 in my desktop - unpacking 2,000-4,000 cRAW or RAW files from the R5 is cumbersome still...and in Lightroom, they can take hours to create previews for - so I often don't. This isn't enjoyable, especially when I only have 10-15 minutes where I can come into a media tower and offload my cards and start quick processing for whoever I'm working for. With the 1DX, this was never a problem at all because of the 20mp resolution where I shot RAW exclusively at all my races. I could offload the card, import to Lightroom, filter by rating, throw a quick edit on all of them, and start the export and deliver quickly. This process - an incredibly large use case for professionals - is dramatically slowed down. So this is why I would love to have the option to say "I don't need 45mp right now" and be able to shoot 20-24mp when I wanted. Ask any wedding photographer if they prefer a D750 or a D850....or a A7III or an A7RIV....or an R6 or an R5. I think an overwhelming majority will take the D750, A7III, and R6.