You can't have that strategic independence in the long term is your capability falls more and more behind others in terms of technology and costs. This also has a ripple effect on your industry at large: Would European companies use this European independent launch capability if it was costly and obsolete? No. Would the European military be able to compete against adversaries? No.
An extreme illustration: would you say that Spain had strategic independent seafaring capability if it had maintained fleet a galleons to this day?
> Would European companies use this European independent launch capability if it was costly and obsolete?
If USA will go hermit mode like at the end of 19th century, then they will have no other choice. And we certainly have signs of US wanting to go into isolation.
An extreme illustration: would you say that Spain had strategic independent seafaring capability if it had maintained fleet a galleons to this day?