Introduction: Exchanges make a lot of fiat on shitcoins and they are not incentivised at this stage for LN nodes as it cost them a lot more than they can earn (maintenance/management), they do it for to have more BTC LN users and but mainly LN potential long term
Exchanges can make money by building infrastructure, here is an example of the 3rd largest (river) https://twitter.com/muteness11/status/1587782925709619202
so its perfectly reasonable for exchanges to grow capacity in line with LN adoption , but I think specialised infrastructure companies and specialised Node Runners will be victorious
I cant think of a risk especially having arbitrageurs in the space and game-theoretic incentive for all participants