However, the good thing is that opening a LN channel is not time-critical, so people can wait for it for moments with low fees. Let's say the fees for a instant confirmation rise to $50 at weekdays at daytime, but go down to $5-10 at night (western hemisphere). Then, observing the current mempool data*, at weekends it's likely that they go under $1 and cheap channels can be opened. And once LN adoption is boosted and many services using it, pressure on the on-chain fees should become lower.
But yes, I guess that if LN adoption depends only from fees, then it can fail, as fees could rise too fast and opening LN channels would be too expensive, like you wrote. So I guess there are additional efforts needed. Service providers, above all wallets and exchanges, should really realize that if they support LN now when fees are still low, they also contribute to a healthier and more sustainable Bitcoin ecosystem.
*For example, according to Johoe, in the week between October 5 and October 11, fees were relatively high, with instant-confirmation rising over 100 sat/byte in several occasions. However, even in this situation at the daily minimum (night in the western hemisphere) they could always be confirmed for 8 sat/byte or even lower, and at Sunday 11, 1 sat/byte again was enough. So there were 2 (decimal) orders of magnitude between the minimum instant-conf fees and the maximum instant-conf fees.
It's also a matter of perception of use.
I have no issues opening 2 very large channels to some providers and a bunch of smaller ones to other places. As I stated elsewhere I was actually using 1 node to connect to the big peers and the another to connect to the small ones and then connecting to the node with the smaller ones.
And as d5000 said you can manage fees by opening channels at certain times. But if I do keep a bunch of channels open AND fees stay high at some point I am going to empty the smaller channels and only deal with larger liquidity providers. That is going to be the issue.
Because, yeah I can say open this with 1 or 2 sat fee because I know it will open overnight on a weekend. But at some point who wants to plat that game.
-Dave