So I guess try to get your first LC job before your personal life gets demanding, then hold on to that job for dear life so you don’t have to grind LC again?
Very skeptical of someone who switches every 2 years... you also become only really efficient after 6 - 18 months.. not only the code / legacy / wider system your stuff integrates with, but also socially knowing all the right people, context of all the bigger processes, a good chunk of domain knowledge ingrained??
People under 35 change on average every 20 months in the US. People who are focused on salary and career achievement. There are a lot of people who get a job and blank out on cruise control and wake up 10-15 years later and wonder why everyone else is making more than them. But the talented people are usually switching every 2-3 years. It's not uncommon for someone to spend an extra year at a company to have a child, plan a marriage.
It’s quite common among the Silicon Valley scene during the tech boom. People bouncing between startups or even between FAANG level opportunities. Switching companies annually even (though not for many successive years).
Sometimes it’s not the worst strategy as the hidden truths of a startup reveal themselves over the course of a year or two.
Your math is wrong. People aren't literally doing LC for 2 months straight without eating or sleeping. If we assume it means you study for 2 hours a day that's only an overhead of 0.7%. I still think that's an overestimation of the time you would actually need.