As with many times when we use the word "should" (and you've used it a lot), the perspective you're sharing is deeply influenced by your own cultural background and might not apply to many people reading.
A few examples: school loans, considering a house purchase to be a sound investment, purchasing once-in-a-lifetime household items, saving for a wedding (from the age of 17!?) or marriage (not sure what you even mean by that if you don't mean the wedding itself?).
The details matter and are personal I agree.
Even if a house isn't right for you, you still need to save for the deposit on an apartment. You still need to buy furnishings for your apartment. You won't even know if a house is right for you until you are mid 20s to 30, so it is probably best to save for a house and if you decide at 30 it isn't right for you roll that money into retirement savings (if a house isn't right for you that means you need more retirement savings)
Relationships - even if you don't have a wedding or kids - come at the time you have those starting to get out on your own expenses. You will need to figure those out.
You just replaced "buying a house" with "buying an apartment", proving my point about cultural bias :-)
I meant, for many people (especially young ones), taking that same deposit to purchase an investment property (which could be a house or apartment, but has a tenant who lives there rather than being for oneself) can be a better deal than buying for themselves.
In the end, buying a place to live in is very much an emotional choice, which is totally valid. But in some locales and for some lifestyles, being a landlord who pays rent elsewhere can be a better financial decision.
This kind of advice was gospel in the 90s.
[should, shouldn't, supposed to, never, always]
These are key words to mentally breakpoint on and more carefully consider what is being said.