It is never really trash, though. High level melee PCs with heavy armor tend to get hit a lot. You reduce a smaller percentage of each hit with the feat, but you also tend to take more hits overall to offset as you advance. In some games, especially those in which DMs prefer to use a lot of low level monsters, it can be very effective all the way up to 20th level.
However, I would not take a Strength ASI in 5E. There are a lot of Strength items in 5E that exceed the bounds of what you can get by raising the strength of a PC through ASIs. They also tend to be favored by DMs as treasure as a selected choice. More often than not there is a Belt of Giant Strength in the party by level 10. As there are so many good melee feats out there, I would not take the strength increase when it might be negated by a magic item soon. This is, howeverm something that I might not say if the DM were to allow the player to reverse an ASI and take a feat instead.
Strength items are common, but usually it is the lower strength characters that benefit the most from them and most (all?) of them are attunement as well. This character already has a 17 strength, it will be an 18 with HAM, so he probably won't be taking a strength-based item even if we find one.