This is amplified for chat programs. They are not really all that technically interesting anymore. They are just "good" at first while they are trying to acquire new users, and providing services for free to so. Simple and light, because there's no need to add gimmicky features to attract new users -- Free is free, and anyway the competition has recently become awful and bloated in an attempt to figure out what the magic feature is that will justify their aggressive monetization scheme.

Eventually good chat program runs out of runway, gets acquired (wow look at that userbase!) or needs to monetize on their own, and becomes the bad chat program. And the cycle continues.