Clearly, the point, is for people who are negatively affected by caffeine to be able to enjoy the taste of coffee or tea.
Decaffeination leaches much of the flavour from tea or coffee, though, leaving it tasting washed out and watery. Decaff tea, to me, tastes papery and flat. Decaff coffee loses many of the higher and lower notes to the flavour, and ends up tasting somewhat bandwidth-limited. (That is, acids and sugars which, to me, taste high and low are reduced, leaving some general “coffee” flavours, but without much in the way of nuance.)
The temptation, with decaff coffee, is to brew it longer or with more grounds. This might help with the feeling of weakness or watery characteristics, but it also gives it an overextracted flavour, leaving it bitter and harsh.
To me, there is not much point. I don’t want to drink overextracted, watery coffee or papery tea, so if I don’t want caffeine, I tend not to drink either.