That's more a commentary on the inefficiency of Teams rather than software in general. Slack and discord both open pretty much instantaneously, and rarely show up in the top 10 resource consumers on my laptop.
I guess there's 'software' and there's software. The problem is in the larger human system that makes it mandatory for me to run Teams on my laptop- there's a reason I complained about Teams and not my college friend's raytracer project, even though both programs have similar resource consumption and segfault issues.