Electronics manufacturing requires some labour, but really not that giant amount of it. The city of Shenzhen alone (not even the greater Shenzhen area municipality,) used to make 50% of world's electronics alone a decade ago. The city back then had way fever people than it is having now.
Virtually any Asian country in the region can provide comparable workforce, or more, and India can probably outdo competitors on workforce n-times over (India produces almost as much engineers per year as China,) but the matter is not about workforce really.
The industry really moves only once in 20-15 years, and it's very cyclical. It stays in the country for 2 turns of the economic cycle, and then departs to the next cheapest location. When Samsung has built its first factory in Vietnam, Vietnam was indeed poorer, and seen lower wages than even Burma, or urban India, or Bangladesh, but otherwise it had very good workforce. Vietnam also gave a complete carte blanche for factories relocating to the country 20-15 years ago, which was better than any government deal in the region, moreover India.
So, Vietnam stole the deal from:
- India - by having much cheaper educated labour, no unions, and much better deals from the government
Bangladesh - by being just a bit more cheap, being closer to China, more developed infrastructurally, and having much better deals. BD government really overcorrected on the last one now, but it's too late already
Indonesia - cheaper, and somewhat better educated labour
- Myanmar - by having no war
Philippines - I really don't understand why the country never got any attention from the manufacturing industry.