I belong to 2 gyms for free, Silver Sneakers for us old guys. I think it is still risky because even if they sanitize everything, you have to hope the others are wearing their masks properly so as not to release droplets. Yes, with heavy sweating from exercise, droplets can travel 12-14 feet. My basement is my gym. I spent a lot of money on personal training over the years, and learned that you can replicate most exercises with resistance bands, like lat pulldowns, rows, chest presses, rear delt flys. Just get the right resistance to challenge yourself.
Got my own TRX over the door. I whack tennis balls against a wall in an 80 square foot area of my basement, chasing them around, and standing on 3/4 inch foam interlocking tiles to cushion the impact on my plantar fasciitis prone left foot. Gets the heart rate up.
I punch a standing punching bag too in my basement.
Gyms now: unsafe to use lockers to put clothes in (what will happen in the fall and winter? Can't hang your jacket or coat on anything in the gym.
Then again, to each his own. Some are going back to the barber. Others are not. I bought an Andis clipper on Amazon and am cutting my own hair standing up and looking in the mirror. Doesn't look half bad.
If you are younger, do what motivates you, using an appropriate amount of caution.