Where is 100k for a house deposit coming from?! Don't most people start with a way smaller deposit? Like 5% is common these days. Yes you'll pay an enormous amount of interest. You pay rent to the owning class one way or another.
If you're buying into the 5% you're probably so fiscally irresponsible that nothing good will come off it. The new builds aren't all magically appreciating in value by 20% every year. And if they did the better house you'd want to move into has almost certainly gone up by 30% or more.
5% down is insane. predatory lending IMHO.
The OP makes it seem like renting and saving huge piles of cash is the only way. It's not. You can buy and save into your house instead. As long as interest plus maintenance etc is the same as what you would have paid in rent, you'll probably end up better off if house ownership is your goal.