That is at odds with the reality of sales
Sales have steadily increased since from 1999 onward & continue to do so, in its peak year (2015) the JK sold more than double the TJ’s best year, so I don’t think the Wrangler brand is showing any difficulty staying relevant with solid axles, in fact it seems to be just the opposite.
http://www.goodcarbadcar.net/2011/01/jeep-wrangler-sales-figures/
https://en.wikipedia.org/wiki/Jeep_Wrangler#Sales
And it looks like the JL is upping the game even more:
https://www.cnbc.com/2018/04/03/jeep-wranglers-just-set-an-all-time-sales-record.html
Jeep is in a classic if it aint broke don’t fix it situation with the Wrangler, while they’re certainly smoothing out the rough edges here & there I think ripping the heart out of the vehicle would be an attempt to ‘fix’ a problem that doesn’t exist. They have plenty of other SUVs in their lineup to satisfy people that want to drive a Toyota Camry that
looks like a Jeep