Much like political dictators, they can be exceedingly efficient and have resources (and authority) to do things in spite of opposing interests.
People who faced with the narrative that countries have a monopoly on a number of aspects of life find monopolies are not a BAD THING(tm), but that they are bad for a consumer market - as a monopoly eventually blockades aspects of the market.
Big companies can suck up all the air in the room by monopolizing talent and making it harder for startups to pay the kinds of salaries needed for top tier AI research. Xerox PARC came up with all kinds of groundbreaking inventions that were never commercialized (by them). For every invention that comes out of a big company, it's worth thinking about whether it might have actually come out faster if it was borne of competition instead of a side project. Or in the grand scheme of things, if corporate taxes were higher and the money was given to a university research lab.
I think the best results may come from the middle ground. Smaller/medium companies are so worried about staying afloat or hitting their quarterly earnings that they have trouble making long term investments. Large companies are diverse and profitable enough that they can afford to blow money on things that might not pan out, but they don't have the same drive -- and in fact have some pressure to avoid being "too" innovative because it could cannibalize their existing products.
See https://ilr.law.uiowa.edu/print/volume-100-issue-5/all-i-rea...
Most people just show up to vote once every 4 years (or less) and make their decision based on the party affiliation or the wedge issue du jour, and the rest of the time pretty much ignore what's going on or don't have the power to do anything about it, which gives a lot of leeway for special interests to slide things in under the radar.
I feel like that is not too far from saying it makes one reconsider communism because good things can happen with authoritarian control.