Should i get new tyres or just go tubeless with my current tyres?

Hello everyone

I bought a Giant Yukon 1 fatbike at the end of winter, and now that summer is around the corner, I’m planning to do a lot of bikepacking with it. The one issue I've encountered is that it feels really hard to pedal even without any bags. Of course, I'm used to gravel bikes, so I'm still a bit of a newbie when it comes to fatbikes.

I asked for advice in my local Finnish fatbike group, and some people suggested switching to Barbegazi tires and going tubeless. My bike came with Maxxis Colossus tires, which are also tubeless-ready. Some say the Colossus is a winter specific tyre? Is it?

My question is: how much better are Barbegazis compared to my Colossus tires if I run them tubeless? I don’t want to spend almost €300 on new tires if they won’t make much of a difference. Some people said the Colossus is already a good rolling tire, but that going tubeless is the real game changer.

Does anyone have experience with these tires?

Link to bike: https://www.giant-bicycles.com/fi/yukon-1-2022