XPS 8700, upgrade from i7-4770?

My desktop is an XPS 8700, yes it does have the latest dell released BIOS available on it, yes it's out of warranty, yes i replaced the graphics card with an RX 570 from ebay, and yes i put the maximum amount of RAM it can handle with the current CPU it has

My current CPU is an i7-4770, and the motherboard is a Dell Inc. 0KWVT8 motherboard (LGA 1150 CPU socket), but the question fluttering in my mind is: can i switch it out with a different one? so i researched online, found the pc-specs website, looked for the biggest choice i got for a higher tier CPU it shows, and it says an i7-5775C cpu is as big as i can go, here's a screenshot (I had to use the firefox inspect function to delete certain portions of the website so i could get this all in one with firefox screenshot, kept scrolling for some reason)

i had to use the archive.org/web website to actually access this because using the url regularly shows an error. i get my desktop is old, VERY much out of warranty, and in overdue need of replacing, and at some point i WILL be getting a new one, maybe from dell, maybe somewhere else, maybe building my own, but in the mean time im going to squeeze every bit of functionality out of it before i have no real choice BUT to upgrade

Dell support & community members, with the CPU socket on it, and with all the defaults still in it, what CPU can i replace my i7-4770 with if I wanted to upgrade to something even a little bit better than it is now (or if my current one ends up fried because of [insert reason here])