I’m an accountant and I think that if you can afford the repayments, you are in a good position.
Let’s say your cash outflow is £1,500 a month on your mortgage - a large portion of that will be repaying capital, ie you are swapping your cash for a bit of your house each month. You are swapping a liquid asset (cash), for an illiquid one (house) but that’s fine. The cash outflow is not wholly an expense - you still have something of value for your money.
Your expense is the interest element each month, which is going to be way lower than it would be if you were renting, plus you have more security.
In addition, the equity in your house will increase over time due to a) capital repayments and b) house price growth. You benefit from the whole £500k of house value growing, including the element you have not yet repaid. If house prices increase by 1%, you make £5k and you can crystallise that in the future if you choose to downsize, or leave it to your family.
On the flip side, the liability (debt) that you repay doesn’t increase as house prices grow (although it may change if interest rates move). The bigger the house value, the more you can benefit from growth.
Finally, as well as being a good investment, and a way to grow your equity, you can use your property to live in too and it will provide security and enjoyment.
I realise it can seem daunting, but the real cost here (interest) is low for the benefit of having a valuable asset and the ability to grow your investment.