That's the part where the market has kicked into bubble valuation territory, when you're primarily seeing multiple expansion driving 40% or 100% type gains.
Microsoft hasn't been able to grow earnings for years. Why do they have a 30 style PE ratio? Why did their stock triple on zero earnings growth? Comparing their growth today versus the multiple, against 2000's valuation, today's value proposition is drastically worse. Or spread it out, compare 1995-2000 MSFT growth, with the multiple they had at the end of that five years, versus 2012-2017 growth and the multiple they have now.