I don't think wizards needed much muggle technology at any point in history. Whatever technology they did adopt, it might have been for practical effects only, at least most of the time.
For example, the train provided a means of transport for the whole lot of students, all at the same time. Before that, the logistics could have been quite complex. I guess that parents apparated their kids to Hogsmeade, but I'm not sure this includes luggage. Dumbledore "sent" Harry's luggage to the Burrow somehow, but Dumbledore was more powerful than usual. Another theory: portkeys following a strict schedule, so no two families would appear at the same time in the same spot. Whatever the case, the train was an excellent opportunity to avoid this messy setting, and, it must be said, an opportunity for kids and teachers traveling on the train to enjoy a few hours of the beautiful English countryside landscape.
As for electricity, they don't really need it because they don't use stuff that runs on it. They have wands for light (and apparently, an unlimited number of almost-everlasting candles), and they can also lit fires without matches (so they wouldn't need electric light, heating systems, etc.). Apart from that, I can't think of any other thing they would use. Telephones or e-mail would be useful, but:
- They already have effective means of communication (even instantaneous).
- Their society is smaller than muggle society, so adoption of technology would be too much of an effort for so small a population.
- How do you align wizard political/economical system with the muggle system? I mean, if you want to use telephones, you have to have a contract and some exchange of muggle money.
Here is, I believe, the strongest argument for wizards to avoid muggle technology. I think anybody who took Muggle Studies seriously realized that they were far better off without all the complications of a society so dependant on companies that provided products and services. Just imagine telling the Goblins they'd have to do regular business with their muggle counterparts (not to mention telling the muggle bankers).