For long runs I’ll try to mimic my race day as much as possible which consists of some chocolate milk and a banana with biscoff butter. (On race day I also do a Maurten drink but I’ve done it enough that I know I can tolerate it fine and I’m a cheapskate).
Same with gels. Use Maurten on race day and whatever is cheapest for long runs.
I did splurge last year and bought Relyte powder for after long runs. Otherwise it has always been Gatorade powder that I’d mix up for long runs. I run early morning so don’t need much hydration.

For most runs it’s a swig of chocolate milk or nothing before the run.