Betting activity can move a market, and is a factor that definitely can affect pricing, but bookies most definitely calculate odds based on their analysis and conclusion of how likely they believe something is to happen.
https://www.onlinebetting.org.uk/betting-guides/how-do-bookmakers-set-odds-and-make-money.html
I wouldn’t fancy betting on us to finish in the top half (as it stands) and still anticipate a relegation battle. Not on of those where you need to keep one eye on the teams further below, just in case you get dragged down, but a full on scrap to avoid it.