Joking aside, the biggest issue is that lightweights were brought in to help nations whose people just aren’t as big as the power nations
Mine is one of them, so I’m biased, but the following countries have had Olympic finalists in the last 20 or so years that aren’t from “traditional” rowing countries; Japan, France, South Africa, Greece, Cuba, Finland, Portugal, Ireland, Switzerland, Uruguay, Czech Republic, Belgium.
Theres extra places for qualification too compared to heavyweight doubles so even more countries are brought in.
Obviously some of the countries above have had the odd heavyweight success too but lightweights have brought in a lot to the sport. Shame, IMO, they’re excluded from the Olympics now