Which is why OM Systems OM-1 mark II is my birding camera of choice. What Canon, Nikon and Sony do are of no interest.
I go out birding most days and see a large number of Canons and a sprinkling of Nikons and Sonys, but not a single OM in the past few years. I occasionally saw an Olympus pre-Covid. Canon and Sony have about 70% of worldwide mirrorless sales and OM are now down to only 2-3% from higher when they were Olympus. They are more popular in Japan but have dropped behind Nikon at around the 12% mark or less.
In terms of practicality for birding, the star OM telephoto is the 150-400mm f/4.5 with the 1.25x TC, costing over £6000 here. Given the crop factor of 2, that is equivalent to an 300-800mm f/9, about the same weight as the Canon 200-800m f/9, costing £2000. Further, the OM sensor is only 20.4 Mpx, compared with 45 Mpx on an R5ii, so the R5ii has an effective extra reach of 50%, like having a built in 1.5x TC. The cheaper 32 Mpx R6iii has 32.5 Mpx, which is equivalent to having a 1.26xTC on it compared with the OM. The lighter RF 100-500mm f/7.1 has an equivalent reach of 750mm on the R5ii, compared with the OM. The cheaper M. Zuiko Digital ED 150-600mm f/5.0-6.3 IS costs £2500, weighs more than the 200-800, and is just a rebadged Sigma with a marked-up price.
As good as Olympus used to be, and it was far ahead in the past, OM haven't put in the development and so Canon has leapt ahead in terms of AF, subject identification and tracking. However, your opinion clearly differs, and there are devotees of M4/3.