The whole idea of location sharing makes me claustrophobic, and I'm single. If you don't have trust in your relationship, you have nothing.
I had a friend who wanted me to share my location with her when I was dating. Seemed like a reasonable safety precaution, so I shared for a time. But this woman ended up asking me why my location was turned off on more than one occasion - as if it were her business. I think the practice lends itself to stalking.
If someone ever asked me to do it again, it would be a hard pass for me. It's not about cheating or being untrustworthy, it's simply a privacy issue. Nothing good can come from someone having the expectation of knowing where you are every second of every day.
Imagine if they simply wanted to sneak over to your favorite store to get you a gift?