We can look at examples where both are accepted. Monero is either ahead or right behind Bitcoin in use. Which is spectacular for how small Moneros userbase is in comparison.
SilentLink, Coincards, NanoGPT, PayPQ, NymVPN, ShopInBit, Porcfest vendors, Darknet Markets, etc all show this when they breakdown what their customers are paying in
Bitcoin and Monero have a symbiotic relationship imo. Different strengths.

