It's been going on since 2013. Thoughts on when it will end?
This is every starting-caliber QB who signed their second contract after 2009. (Note: there were none in 2010, 2011, or 2012).
Data listed include the year they signed that 2nd contract, their rank the prior year (based on QBR, minimum of 200 attempts), length of contract, total amount, average amount, and what percent of that year's cap the average amount is.
2013, Ryan, 6th in 2012, 5 yr., $103.75M, $20.75M (16.87%)
2013, Stafford, 25th in 2012, 3 yr., $53M, $17.67M (14.36%)
2013, Flacco, 14th in 2012, 6 yr., $120.6M, $20.1M (16.34%)
2014, Smith, 13th in 2013, 4 yr., $68M, $17M (12.78%)
2014, Dalton, 14th in 2013, 6 yr., $96M, $16M (12.03%)
2015, Wilson, 11th in 2014, 4 yr., $87.6M, $21.9M (15.28%)
2015, Newton, 2nd in 2014, 5 yr., $103.8M, $20.76M (14.49%)
2015, Tannehill, 15th in 2014, 4 yr., $77M, $19.25M (13.44%)
2016, Luck, 33rd in 2015 (7 games), 7th in 2014, 5 yr., $123M, $24.59M (15.83%)
2017, Carr, 9th in 2016, 5 yr., $125M, $25M (14.97%)
2018, Cousins, 13th in 2017, 3 yr., $84M, $28M (15.8%)
2018, Garoppolo, not rated - 7 career starts, 5 yr., $137.5M, $27.5M (15.51%)
2021, Wentz, 4 yr., $128M, $32M (approx 14.88%)
2021, Goff, 4 yr., $134M, $33.5M (approx 15.58%)
I copied the rest of this post from a post you wrote more than a year ago. Seemed pertinent ...
In 2013 and 2014 Wilson and Seattle had been to the superbowl twice, winning once. In 2015 he was up for his 2nd contract and got about 22 M, which at the time was about 15.3% of the cap.
Meanwhile in 2018 Garappolo got 27.5 M, and that's after starting (at the time he signed) 7 games total in his career. In 2018, that contract was around 15.5% of the cap.
Superbowl winning qb, and then a qb with limited starting experience, and they got the same rough percentage at 2nd contract time.
AlbaNY_Ram