DELL optiplex 7010 case swap

Dell uses proprietary and undocumented front panel connections.  Case fans are proprietary and the Dell BIOS senses the fans. Other fans will work just you will get a fan failure notice at power on.  Motherboard mounting holes are only partially ATX but usually enough to hold the motherboard in place.  You will likely need a new/full size power supply too.

If you can deal with the non standard front panel connections, power supply and the fan issue, go at it.

I build my own and use BeQuiet cases as I need a quiet PC for my recording studio.  Cases run from inexpensive (under $50) and up to several hundred.  Look over the cases at www.newegg.com

the only hurdle is power switch on motherboard, here is pinout

https://www.dell.com/community/Optiplex-Desktops/How-to-connect-a-5-pin-power-switch-to-a-motherboard-that-uses-2/td-p/7322005

otherwise the board uses standard 24 pin ATX power and appears to have a standard form factor.