I actually don’t mind receiving every single one and they don’t make me worried at all. I get one, I might not see it, this usually means I’m at home not planning to use Monzo within next mins. If I happen see it, I’ll acknowledge.
I didn’t have any failed payments, so I didn’t have situation that text saved me from failing card payment. BUT because I receive them all (or pretty much all Monzo thinks we should get), at any given point in time when using Monzo card I can be really confident that it will work. 
I do expect that volume of them will decrease slightly, once card processor is out of the way, simply based on GPS-caused problems right now.
I totally get why intensity might be ‘too much’ for some users, but then Monzo would face problem of categorising hiccups into 2 categories, less and more serious. Arbirarity of this decision might confuse users, with statements like “this wasn’t serious enough to get a text, why did I get it”. Plus, sometimes issues seem less serious, but it turns out they are serious and the other way around. First 5 mins of investigating issue don’t always allow to make assesment and waiting any longer than that defeats the purpose. 