Great shot!
Looking at list of Canon medium telezooms I have narrowed my choices to just two:
(1) stick with 55-250 STM with IS.
(2) upgrade to 70-200 f4 no IS, for
(a) possibly better AF
(b) presumably better image quality
© 1 stop faster at long end
While giving up
(x) IS
(y) more zoom range at both ends
(z) lighter weight and size
Money aside, is that a worthwhile trade off? I’m thinking not.