Is the International Day Pass seriously the best way to use my phone number abroad?

Heading to Europe for a few weeks with an unlocked iPhone...on past trips I've just bought a local sim at a cell phone store when I arrive and for less than 20 bucks I have good service/data for the trip, but in the process don't get calls/texts from people back in the States who don't know to contact me via WhatsApp.

Seems silly that ATT wants $12/day and then caps this at $120/month...is there a way to somehow view my texts/voicemail abroad with wifi and not get stuck with these exorbitant fees? I know in the past carriers would just charge insane international roaming fees and that the $12 is cheaper than that, but still wasting $100 in the process. I could handle the excessive charge if my phone was being subsidized & locked to ATT, but I bought it outright to not deal with being tied to a carrier in the 1st place.

Cheers!