Should I remove the screen protector from my 2021 14 inch macbook m1 pro?

If it's been t here for a long time and is causing no harm, I'd leave it alone.

Over time, it may have become more tightly adhered and pulling it off might damage the screen. I suspect not, but you just never know.

You might not get an answer because Apple does not recommend using one, so there will be very few who actually would. Older machines were made differently and had more space between the screen and keyboard, but newer ones are so thin that there really is no room for it.

I've seen enough damage from screen protectors reported here that, as long as it does not interfere with the image on-screen or proper closing of the lid, I would not touch it.

If it has damaged the screen, you are facing a US$500-600 repair. The display assembly in all Retinal Macbook Pros is a sealed unit; damage to any component requires the entire assembly to be replaced. Costly.

As this was a recent purchase, you might approach the seller and ask them to remove the protector. They should refund your money or pay for repair if damage has occurred.