Some Let's Play videos are hard work. Some aren't. Blind LPs are not really that much work, but if you're like some people out there who complete 100% of Final Fantasy or Dragon Quest games then yes it can be hard work because you still have to edit the videos, come up with meaningful commentary, and research the game.
That said, you shouldn't be doing it if it is a 'just a job', or if you don't enjoy it.
This dude is in the top 3 worst youtube let's play personalities. That is a shockingly high spot with such a deep bench of awful youtube let's play personalities.
A guy who's never had to work under a deadline before in his life is saying there are deadlines to uploading a video of him playing a 13 year old video game to youtube.