A lot of IC historically become managers not because they particularly care about doing performance reviews but because they want more influence and to work at a larger scale. This leads to a situation of people managers who care less about managing people than managing delivery and technology strategy. The best of those also have a lot of empathy and inadvertently are good at people management.
Another reason, often related in my experience, is a lot of companies careers plateau for ICs pretty early on. Your comp stops growing beyond COLA, titles exhaust, and despite being young you’re at a terminal career velocity. The only thing way to break up is to become management. This isn’t surprising - who controls promotion and comp other than managers, and why on earth wouldn’t they structure things to reward themselves and people like them? There are many companies that have recognized this and created IC paths parallel to management, at least up to the C level. However the relative difficulty in achieving them is disproportionately weighted against the IC vs manager. At Amazon there’s a crap ton of VP and Director managers. But it’s absurdly hard to get senior principal or distinguished engineer. The rationale is they want to keep the prestige of the level high for IC. But that’s weird - the prestige of the same level in management must therefore be low and why is the bar different for the same level if you’re managing vs building?