Certainly trading with BTC is the safest option. Trading with alts, especially some bump/dump shitcoins, very easily fills the bag with worthless numbers of some promising projects.
For those who are experts it may seem easy. But for those who are studying, it is quite easy to make the pocket run out again. Indeed, Bitcoin is the most profitable investment instrument today. But there are many risks for those who cannot afford it and make them ruined.
Trading is a choice of ability. Everyone has satisfaction with their own style. But so far I have been using the Altcoin/BTC pair to increase the amount of BTC. Not adding to my Fiat. What I believe is the development of the price of BTC which will continue to get more expensive. Maybe taking advantage of all the trading features is the best thing, but I can't afford it. Because so far the crypto trade has varied. IMO