You can't believe how high the demand is for frontend devs who specialise in accessibility. These days I have at least one meeting a week with a potential client and I'm not even actively searching.
They even ask for up to 3 or 4 full days a week for long-term commitments and for willingness to travel regularly. In some countries it's really hard to find local experts.

@matuzo I need to add an asterisk to that affirmation

The demand is high* if you live in a country with decent accessibility legislation. Here in Colombia, for example, this is not the case.

My suggestion for folks outside the USA or Europe is to learn English, which helps get more opportunities, that certainly helped me out!