I have never got the “you spend more on the car maintaining it than the car is worth” thing. The value of a car is in its utility and effectiveness as a means of transport, not it’s monetary value. If it costs you £2,000 in maintenance keeping your paid off 15 year old car on the road (that’s worth £100 scrap), but it costs you £4,000 a year financing a new car (that depreciated by 1/3 of its value as soon as you drove it off the forecourt) then your old car is better value. It does the same thing (get you where you want to go) at less cost … but I’m sure that’s just me … anyway …

Entering service in the ‘50s the decade before the Boeing B52 and still in active military service to this day …

• McDonnell Douglas Phantom F4
• Lockheed Martin C-130
• Boeing KC-135 (it’s a converted 707)
• Lockheed U-2
• Dassault Mirage III
• Mikoyan Gurevich MIG-21

And showing that good design against required specification really is the thing with the 2^nd longest production run of any military aircraft (the C130 above being the longest) I give you the:

• Antonov AN-2

Entering service in ’40s and still in active military service today; admittedly with North Korea which is probably not the best endorsement however they are still flying … and still in combat operations by Azerbaijan last year (2020) … I know!!! ; admittedly as a Unmanned Combat Arial Vehicle (UCAV) most probably as a decoy drone (see my Van Nuys Class Decoy Unmanned Combat Arial Vehicle posted earlier (which was based on Azerbaijan using the AN-2)), but purported to be carrying a bombing payload as well (although that could just have been to make sure the Armenians shot it down (therefore making it more effective in its decoy drone capacity)).