Very good information. Multidrug resistant strains do exist and that would be a nightmare. We must take our medications regularly and should not fetishize about mixing and matching strains (but this concept of mixing and matching isn't well understood by the scientists).
The good news is it is extremely unlikely that someones genotype test will say that the patient's HIV is resistant against all drug classes. Even if that unlikely case happens, there's still hope. A new drug Lenacapavir brought down the viral load in 88% of heavily treatment experienced patients with multidrug resistant HIV in a recent clinical trial. It is so wonderful to live now compared with 1985.