Leetcode is the current meta of the developer career. As all metas, you can choose to ignore it, but if you want to maximise efficiency, you need to play by the rules.
Also many companies have systems that encourage this. For example, currently I am a mid level developer at some large software company. To get a promotion to senior level, I need to "consistently prove I can work at senior level". In practice this means spending about 2 more years of assuming the responsibilities of a senior, delivering large impact projects, coordinating team members, writing endless documents, and get a committee to approve my promo. After all that effort I will be given a new title and a meager raise.
Alternatively I can spend 3 months grinding Leetcode and Systems Design, interview around with a few companies, and cross my fingers. If I'm lucky I'll get a senior level offer. If I'm really lucky, I'll get several, engage them in a bidding war and substantially increase my compensation.
Also many companies have systems that encourage this. For example, currently I am a mid level developer at some large software company. To get a promotion to senior level, I need to "consistently prove I can work at senior level". In practice this means spending about 2 more years of assuming the responsibilities of a senior, delivering large impact projects, coordinating team members, writing endless documents, and get a committee to approve my promo. After all that effort I will be given a new title and a meager raise.
Alternatively I can spend 3 months grinding Leetcode and Systems Design, interview around with a few companies, and cross my fingers. If I'm lucky I'll get a senior level offer. If I'm really lucky, I'll get several, engage them in a bidding war and substantially increase my compensation.
Draw your own conclusions.