unfortunately that is not true. The requirement for 99% of us has been withdrawn. Included in that 99% are those of us with Education, Business, non immigrant O and O-A and tourism visas. The list excluded from the TM28 is so extensive it is hard to find anyone who needs to fill one in now.
Yellow book is proof of address, I have used this for renewal of driving licence and when I renewed my British Passport.
Pink ID is used for general ID meaning no need to carry passport or copy of it. It can be used to check into hotels. I use mine for entry to National Parks and attractions. My success rate of getting the Thai price when accompanied by a smile is about 8 out of 10.
I recently booked my COVID-19 vaccination online with it.
Personally I definitely think it is worth the hastle to get it. If you are regularly changing address it probably isn't.
If you really want a Fit to Fly certificate then contact Dr Donna. She needs a negative COVID test and will conduct an online consultation and issue the Certificate. All for 400 Baht.