There's absolutely viruses that we tolerate currently and take basically no effort to fight, because in the vast, vast majority of the population they're benign. I had an organ transplant a couple of years ago, and as part of that I now have to do monthly blood screening for some of these benign diseases (CMV and BK) since they aren't as benign for someone on strong immunosuppressants.
Maybe this is a selfish thought, but moving towards tolerating diseases objectively increases risk for people like me who can't tolerate diseases to the same extent as others, and others tolerating them more increases the odds that I'll catch them, so this isn't a medical advancement I'm particularly excited about.