Spigen Ultra Hybrid has grippy sides & is pretty easy to take on & off. It's usually around $15-$16 on amazon. TPU sides, polycarbonate back.

https://www.amazon.com/Spigen-Hybrid-Anti-Yellowing-Technology-Designed/dp/B096J9ZSG1/ref=sr_1_1?crid=WY5UX3W4EU2R&keywords=spigen%2Bultra%2Bhybrid%2Biphone%2B13%2Bpro%2Bmax&qid=1678412802&sprefix=13%2Bpro%2Bmax%2Bultra%2Bhy%2Caps%2C127&sr=8-1&th=1