#bitcoin is still the cheapest and fastest. There is no alternative which would allow you to send thousands or even millions of dollars in matter of minutes and pay only cents or maybe couple dollars on fees during peak periods.

And if you want to pay smaller amounts, you can use lightning ⚡ which is essentially free. And most merchants that accept bitcoin accept lightning already too.

Block space being limited is a feature of bitcoin that ensures there is security budget for miners in the future.