I would argue that the high salaries in the software industry have siphoned technologists from other industries that make physical products. Some of that is intrinsic, since making stuff has smaller margins than pushing bytes. But a lot of it is hidebound business practices. For example, should a manager always make more money than their reports? In many industries the answer is yes, which is a rejection of supply and demand in favor of a social hierarchy. There is also incredible bloat in supervisory roles, again because of the artificial money and prestige. Some companies would seemingly prefer to slowly die than pay needed employees a market rate, market being a national market spanning industries (some skillsets are fungible like that).
Personally I think it's more likely that the low salaries in other areas of technology (particularly physical products) has pushed people to software, rather than high salaries in software pulling them. Same effect in the end but I think the race-to-the-bottom in manufacturing, machining, and physical product development began the cycle. Soaring software salaries followed.
