gaming does go on

If the cheapest flight is the last flight of the day then yes, book it and then change to an earlier flight if you are free and its available, provided you are prepared to wait for the last flight if the earlier ones are full

I and others on here have done this.

If lots of people do this then the cheap fare buckets in the late flights fill so it becomes less attractive

Its not so easy to book a cheap flight at say 2pm and then hope a seat is free on a later flight if you are busy till late afternoon