A quick comparison for fun.

Sun and Moon (Nov 2016): ~$650 million*
Ultra Sun and Moon (Nov 2017): ~$350 million*
Let's Go Pikachu & Eevee (Nov 2018): ~$600 million*
Total = $1.6 billion

Pokemon Go (June 2016): $2.5 billion

*Estimated based on RRP x Units Sold. https://t.co/YRhN3LAzSl

— Daniel Ahmad (@ZhugeEX) April 3, 2019