Is there a way to keep all your gears (specifically chainring) when using a mid drive kit?

Sorry this is a dumb question.

I'm looking to repurpose my old streetbike from highschool. I wanted it to be a traditional bike first and ebike second (will primarily not be using a motor) so keeping all my gears is very important to me.

I've considered hub motors but I'm 300lbs (I know, I know) and honestly don't think it would be enough for some of the hills here, I also don't like the added weight being the part of the bike I need to spin up every time I accelerate. Ideally I just want a normal bike that I could lazely use only throttle if I'm having a bad day.

I got really close to pulling the trigger on a few hub driven Bafeng models and I'll probably go this route if there really isn't a reasonable way to maintain all prior gears with a mid drive, I just am hesitant because I love what mid drive offers in terms of efficiency, torque sense assist, and response time. I was also trying to keep the whole conversion under $1000-$1200.

Is this possible or should I just settle with a hub motor?