OP's title is "We haven't invented anything worth mentioning in decades". The examples of Cubitron II, Novec, Avagard, etc were in the last 15 years. Innovations that go into EVs (fire re--rdant material, light weighting, etc), while not se-y, does help the company grow. Look, even Apple hasn't had "breakthrough" innovations in awhile but they continue to grow.
My point is that 3M continues to innovate. New product categories (aka class 5) are notoriously difficult. And quite frankly, 3M does stink at class 5, but as a lab person, I take offense to "we haven't invented anything worth mentioning in decades". What I do see is that 3M management can't pick winner projects. As a result, the strategy to have fewer, bigger NPIs have not resulted in growth. IMO, 3M should go back to 'make a little, sell a little' model so the market can decide ... not 3M management.