Is there a serious reason to pack valuable space with a high level but bulky and heavy old benchtop test equipment (like 90' HP, Agilent, Keithley and so on)? Besides that, old equipment have a less informative displays, consumes more electricity, is less compatible with nowadays technologies.
Finally mentally it makes you feel stuck in the past
Or... I am wrong?
It's not a simple thing to answer (of course right?).
You say "bulky and heavy old benchtop test equipment (like 90' HP, Agilent, Keithley and so on)". well it's not all "bulky / heavy" stuff. 90's test equipment isn't all like that. In fact some of it is the same size as much modern stuff. In the pic you see two 90's hp kit alongside a very new Siglent scope (SDS2202X-E). The hp kit is an hp 5385A 1 GHz frequency counter, and an hp 437B power meter. The older stuff works fine and isn't expensive compared to brand new equipment of the same type, isn't bulky, and doesn't use megawatts of power.
However, an older CRO of that era would be bulky (depth) and use a lot more power, and for the price point, wouldn't have the bandwidth of the SDS2202X-E (opened to 400 MHz). So you see these different generations of equipment alongside one another.
In the second pic you see two units of the bulky / heavy class of which you speak. The Agilent 8648A RF generator cannot be replaced with a new item of the same caliber of design for the same money. You'd have to spend a whole lot more for brand new so I make room for that. Below it is an hp 5334B frequency counter. It can be replaced with a smaller unit (which I already showed). However, some of these things are items I used in my career and I choose to have them out for sentimental reasons (but they do work very well).