>>4220085resolution change (not as significant in terms of influencing the final output as you might think), larger viewfinder, higher res screen, slightly smaller and lighter body, video upgrades (no record limit, higher res) are probably the biggest reasons to switch. if you are OK not having the absolute best in those categories, you can save quite a bit with an X-T4. I've seen them around $1000 consistently.
https://cameradecision.com/compare/Fujifilm-X-T4-vs-Fujifilm-X-T5 