I was the same with my 7Dii, bought on thefirst day of issue. It went everywhere, coupled to my Sigma 150-600 Sport after I bought that in 2015. Got a lot of great results. Flight shots, particularly in the high winds of the autumn migration at Tarifa on my annual trip were very hit and miss though, as the bird bounced on the wind and the same gusts caught my lens hood. Keeping that centre cluster of focus points on the birds was a feat of endurance.
Since my R5 arrived (4 months after ordering, 3 weeks after its release) my 7Dii has lain forlorn in the cupboard. The R5 worked well with the Sigma, but after 4 months I splashed out and took the plunge with the RF 100-500, taking the hit on the full frame and reduced focal length, but a massive improvement in cropability. Another bonus is that the R5 and 100-500 weigh exactly half of the 7Dii Sigma Sport combo. the first time I went out with them it felt like I'd left the camera at home. Saying that I didn't mind the weight of the sigma when I was using it. Muscles develop.
I'm just back last month from Spain for the spring honey buzzard migration, my R5's first trip abroad since that damned Covid and the R5 was a revelation. Instead of 90% missed focus on flying birds in gale force winds, the percentage was reversed and I came back with thousands of in-focus shots, many of which I binned just to reduce the numbers. That eye detection was a dream. (pics below).
I'm now suffering the frustration to see if I'm in the next batch for R7 deliveries. I ordered from WEX at 10am on the first day, but that still wasn't early enough for a delivery this week. I'm keeping my fingers crossed. When the R7 arrives it will be my bird camera, with the R5 for landscapes, events, people and stuff that I used to do with a 5D iv (recently sold to make way for the R7). That extra reach with the eye detect will be a killer when I go back in the autumn for the outward migration.