I can jump in here as well. V and MA are two very strong payment companies. So I would absolutely consider both to be foundational stocks. Its important to note that there are likely hundreds of good solid US Foundational stocks- the market is so much bigger than here in Canada and there are many, many global behemoths.
If I was to pick one between the two, I'd be grabbing Visa here - in fact I might soon. It is better valued than MA and both have smiliar expected growth rates (in the mid teens). I also find Visa has been a little more progressive in the steps taken to adopt crypto. The yields are non-factors.
ABT - another good one. Nothing wrong with holding Abott and is a leading medical device maker. It is reasonable valued here, especially after recent pull bank. Absolutely zero issues snagging ABT here and has expected growth rates in the low teens which is solid. Once again, the yield here is a non-factor with it being less than 2%.
In terms of AMT, I do like the fact it is an infrastructure play as it owns and operates cell towards. Since it operates as a REIT, you'll have to be mindful of the distributions and the taxes associated with them. From strictly a historical perspective...looks to be fairly valued, but the entire industry does look a little expensive TBH. In this space, another good option is Crown Castle (CCI). Once again however, it ain't cheap - i actually think AMT is better priced than CCI and has managed to post higher growth rates. Interestingly, they have very similar performances. I've attached their 3YR charts. It seems when one outperforms, you buy the other and vice versa.
Mat