There is widespread agreement here that we would welcome multimeter manufacturers being honest about little meters without CAT ratings. There is absolutely a place for those meters.
What is inexcusable is lying about CAT ratings, because it could put someone in danger, for example if some unwitting buyer at a power company buys fake-CAT-rated meters for the company’s linemen who actually are working on dangerous high-energy circuits. The fake paper trail makes it seem the meters are suitable, and the guys using them are at serious risk if something goes wrong. Those meters might have been perfectly safe for 99% of buyers, but not for those linemen.
Well, the fact that the budget meters do not comply with their declared standards would have to be proven in individual cases.
It is usually simply assumed in this forum.
No, it isn’t just assumed.
When you see a meter with a 250V AC 5x20 (or 5x10!) glass fuse, you know it is by definition not compliant. When you see one with no fuse at all (on the current ranges), you KNOW it isn’t compliant! When you see a meter with input PCB traces with a screw running between them, using up all of the space between the traces (such that it is almost shorting them out) you know there is no way it could pass CAT rating testing. When you see a meter that explodes when subjected to the CAT rating’s test conditions, you know it isn’t compliant.
There do exist properly CAT-rated meters without fuses: meters without current ranges.

I mention fuses a lot because they’re an easy first sign of… effort. Do you think the big manufacturers would use cheaper fuses if they could, and still meet the stated rating? Of course they would. It’d be cheaper for them and less annoying for users. So the fact that the big names use the $$$ fuses is a strong indicator that the CAT ratings cannot be met without those fuses.
But it’s not just fuses: if a meter lacks real input protection, it’s not likely to meet CAT ratings. Again, we see what the big names do (adding things like gas discharge tubes and other overvoltage devices), which the cheap brands leave out, and which the big brands would leave out if not necessary.
And there are meters that, regardless of CAT rating printed on them, do clearly make more effort than others, because of using better fuses (like British-standard ceramic mains fuses), and having decent input protection otherwise.
I don't know enough about it.
Which is why it’s really, really annoying that you keep inserting yourself into those discussions, declaring that everyone else is exaggerating the risks. You don’t know nearly enough about the subject to be lecturing everyone else about it!
Your ignorance is not of equal value as others’ expertise!! But yes, as Dave Jones said, the CAT I and II declarations on the front of a meter will be removed in future anyway.
It’s bizarre to me that they decided to eliminate the lower categories. :/
That would be a good opportunity to do away with dubious CAT ratings completely.
How would it? The problem is that cheap meter makers always slap either CAT III or IV on meters, even ones that very obviously cannot meet those ratings.
Personally, I am interested in other things, such as accuracy and precision/resolution, measuring range etc. etc.
I have never bought a DMM because of CAT ratings.
And that is absolutely fine. But it’s irresponsible to tell everyone else here that they don’t need to observe CAT ratings either, and it’s absurd to basically insult people who try to take a more nuanced position.