Learn Italian: Si conseguirebbe lo scopo tramite questo metodo. - One would achieve the purpose through this method.

While you could use con (with), tramite (by means of / through) elevates the register. It sounds more professional and precise, which matches the formal tone of the verb conseguire (to achieve). It specifically highlights the method as the instrument used to reach the goal.

Could I use mediante or attraverso instead of tramite in this exact sentence?

Yes, mediante is a perfect substitute here and belongs to the exact same formal register. attraverso also works well, though it can sometimes carry a slightly stronger figurative nuance of going 'through' a process step-by-step, whereas tramite simply states the tool used.

Why does the sentence start with Si rather than a subject pronoun like Uno?

This is the impersonal si construction, which is much more natural in Italian than using a literal word like uno for 'one'. Because lo scopo (the purpose) is receiving the action, it acts as the grammatical subject, making the literal structure closer to 'The purpose would be achieved.'

I usually see ottenere or raggiungere for 'to achieve'. Is conseguire a common everyday word?