I’ve recently been to Tenerife and I’m refloating this thread to add a chart with all the current accessible beaches in the island updated in 2022. The chart is in Spanish, but the icons are quite self-explanatory. The columns on the chart are: City, Beach, Parking for disabled people, Access to the beach by ramp, Accessible showers, Accessible restrooms/changing rooms, Boardwalks, Rest area (usually a wooden area a few meter from the sea), Beach wheelchair that floats in the water, Beach crutches, Availability of staff to assist you get to the water, Beach type.
https://sinpromi.es/wp-content/uploads/2022/07/PLAYAS-ACCESIBLES-EN-TENERIFE.-VERANO-2022.pdf
As you can see, there are many options. The south of the island has great weather all year round and is specially accessible, so I’d say it’s a great destination if you want a relaxing vacation.