Personal Finance

I'm speaking from an American POV on credit cards: getting a good credit score requires doing a lot of things that don't really make sense. I'd just make your peace with that and play the game. Opening as many credit cards as possible, never missing a payment, and sending a small payment through each one once a year to keep them active is an extremely good way to build a solid credit score. Before you read further, please note that opening credit cards temporarily dips your credit score due to hard inquiries, but all forms of credit score dings are removed after a specific amount of time based on their severity; generally you can expect hard inquiries to go away after ~12 months.

The system encourages you to have a lot of accounts, and it encourages you to have a long average account age. People who never use credit cards may have a poor credit score due to lack of history, and people who only have ~one long-running credit card will have a fragile credit score due to the average account age being prone to literally breaking in half as soon as they open any other credit account. Opening as many accounts as early as you can will temporarily dip your score, but it will come back much stronger. Sometimes you'll get rejected for a credit card and will still have to eat the hard inquiry, so it's a delicate game of trying to open accounts and also trying not to appear too desperate. Having a lot of income also helps credit card companies be more amenable to your thin history.

Also as a last note since you seem like someone who "takes money seriously" enough to not be in debt: at least in America, credit cards are great for your finances as long as you pay them off. Credit cards do not charge you any interest or fees as long as you pay your balance on time, and generally you shouldn't be applying for any credit cards that have an Annual Fee charge. It's not too hard to get an unconditional 2% cashback card, which means they will give you 2 cents back for every dollar you spend (this doesn't count as taxable income). You can further diversify to get specific 5% cards for your most-used categories like gas and utilities.