I've seen that same figure for YT ad revenue alone. sponsorships can range from $0.015-0.030 per video for channels with 1k to 50k subscribers.

at a biweekly cadence, they'd need ~6M views per video to hit $150k with ads alone. if you figure another $0.025 per view for sponsorships, then they would need 6M views per year or about 240K per video.

looking at Patreon stats, it seems reasonable to assume that a channel with 25K subscribers could pull in about 1K Patreon subs with effort. if each is paying $5/mo, then that would add another $60K/yr in revenue (though I imagine a lot of that would get eaten up by fees and extra costs.