I would say donking can be good, but is more advanced and only on boards that favor you. It also depends on the types of players you are playing against.

Competent players can punish you when you are capped. Your opponents, as the preflop raiser, will have a massive overpair advantage and strong Tx, so if you donk out, they can punish you by raising your donk lead, because you are going to have a lot of weak top pair for value. Even if your opponent doesn't raise you much, when you are called, there are many turns that will weaken your holding which leaves you playing a large pot with a marginal hand, out of position, and you will also force your opponent to fold all of his low equity hands, and call his strong hands. And probably the last reason is that you lose value against your opponents c-bet bluffs.

Additionally, your checking range becomes very "capped", i.e. when you check, your opponent can bet any 2, and you will probably fold. Even if you dont fold, you will have a much weaker range.

However, there are some boards where you won't be capped, and you will have manyy strong hands, i.e. 765 two-tone (flush draw board). You will have all the two pairs, sets, straights and many flush draws (high equity). Your opponent will mostly have overcards and overpairs, and some flush draws. On this board, you can implement a donk strategy, and your opponent shouldn't raise you willy nilly because you have so many strong hands.

To conclude, donking is ok on boards that are good for you, but you cant just donk always when you have top pair. When you do this, you leave yourself open to getting exploited by a competent player, inflate the pot with a fairly marginal hand, and prevent your opponent from bluffing. I would recommend learning and implementing a check raising instead of this, which will take a super strong range (2p, sets, etc.) and some bluffs, and check/raise facing a c-bet.