If I had the means to do both zooms and primes I would. But I'm not giving up my 1.4L primes. The zooms look incredible and it's VERY tempting (especially now that we will have IBIS moving forward) but I love my 1.4 too much. I'm far more tempted to get a 24-70 f2.8 IS. I need a quality all-arounder but I'm not gonna spend $3000 for one. For someone who is building a kit (no lens library yet) the f2 zooms make a LOT of sense. Buying a '35 and 50 is more than the f2 zoom (provided you are willing to sacrifice 1 stop on EF and 1.5 on RF)
Well, I already had 24, 35 and 50 1.4 + 85 1.8, I sold them all, after work with them for a few years. Was a hard decision, but lately I was stopping down to 1.8 - 2.2 and only using the 1.4 when the light was really low. Also, working as a wedding photographer, I noticed so much difference in my last works, This plus to change focal lengs so fast having a great aperture, was a step ahead on the work without losing quality, and just a little bit of bokeh / light. In a balance, it deserves the change. Of course, this is only my personal experience and everyone must look for his needs