Post History

It could be OK if you are asking about technology reasons why a class of products will be phased out.  Asking about forces that cause similar things in the past should be OK too, as long as the reasons can really be known.

For example, asking why transistors replaced tubes is fine since good technical reasons can be given.  If it were the mid 1940s now, asking <i>"Do you think transistors will replace tubes?"</i> would be off topic because answers would be just speculation and opinion.  However, you could ask <i>"What advancement in transistor would be required for them to replace tubes in audio applications?  What research is currently being done that might lead to such advancement?"</i>

As for your question about larger SMD capacitors, if you ask the question so that answers can cite measurable market forces or technical issues, then it would be fine.  If you ask in such a way that just encourages people to chime in with their personal opinions or to speculate, then it would be off topic.