My take on this question: it depends
For starters, a lot of etched sets give you etched parts for the sake of giving you etched parts. Many are not an improvement on the kit’s plastic parts, and frequently are actually a step backwards — like providing etched headlight guards for vehicles that in the real world had them made from steel tubing. However, this is a matter of choosing the right set (that doesn’t do this too much) and only using the parts that are actually an improvement (rather than always using
all of them).
However, just as important to me is: what kit are you going to use it on? In general, I would consider using etched parts on a 1970s or ’80s kit as throwing pearls before swine. The plastic parts of these kits are so far below today’s standards that adding etched bits is, really, a waste of effort, time and money. If you buy an etched set, you probably want a detailed model, and for that you would be better off buying a more modern kit of the subject that is already more detailed than a 1970s one even without adding etched parts. At that point, you can then always decide to buy an etched set to make it even more detailed, but chances are that, say, buying an AFV Club kit instead of a Tamiya kit of the same vehicle will give you all the detail you want. Especially as a modeller just starting out
(And sure, many of those more modern kits are harder, or at least more fiddly, to build — but I can assure you that building an AFV Club kit will be easier than building an ancient Tamiya kit with an extensive set of etched detail parts.)
