Of course it all depends on exactly what you are trying to do. If you are trying to do a precision alignment, then accuracy is important.
Bt if you are just trying to do some troubleshooting, then it is not so important (just like having all the different scales).
If there is no sound coming out of a loudspeaker, and you should be measuring 20VAC on a loudspeaker cable, but if you meter is wrong and either reads 15 or 25V, is it really important? NO.
You are getting voltage at that point, so the problem is somewhere else.
Same goes for impedance/resistance.
Let's say you should be reading 5.3 ohms resistance on a 8 ohm loudspeaker. But your "cheap" meter is showing 4.5 ohms. Is the loudspeaker likely to be bad (especially if the complaint is no sound)? NO. The problem is still somewhere else.
Lots of troubleshooting can be done by just being in the ballpark.
Now if you are doing specs for a spec sheet or setting precision voltages, then that is a different story-and you need more accurate gear.
So it begs the question-What are you here to do? And what do you need to do the job?
Many times when doing troubleshooting, I grab the meter/tool that will give me the quickest results to help me narrow it down, not always the one that will give me the most accurate answer. Unless that is what I need to do. and then I will grab the tool that will give me the most accurate answer.
I remember in my first TEF class, the theme was "What are you here to do". And don't waste time taking measurements that really don't matter to the customer and you don't need and do nothing to guide you to the actual problem. They may be interesting, but not needed-and who is paying you-and for what?
If the complaint is there is a hum in the system, then measuring the reverb time is really not doing you any good.
With a tool that gives you all kinds of options, you can waste a lot of time doing/measuring things that will not guide you to the answer any better than a lesser tool.
And for the example above, the problem was the speaker wire was chewed through by a rat. So if the voltage was "off" coming from the amp really doesn't matter. All you needed to know was that there was signal coming out of the amp and that the loudspeaker was not open (resistance measurement).
I'm not sure what the point of this post is-so sorry if it is just rambling a bit.
I guess I missed my whole thing of "getting to the point"