If you're under 40 and don't (and have never) owned a property then, assuming you want to earn a property, you'd be better off with a LISA. You might make slightly less (assuming a Type 2 SL) but you'll be able to access the funds for a mortgage deposit rather than having to wait for retirement. This would get you out of paying rent earlier (freeing up capital for more investing) and then you can make the just of Salary Sacrifice once you're a higher rate earner (young and on £40k, I'm assuming an upward trajectory.)

As you can tell this answer is very life goals-dependent, because it's a life goals-dependent question! Do you want to buy a home? Do you want to retire early? Do you want more disposable income in middle age? Set goals, then methods. Just saving/investing as much as possible is putting the cart before the horse.