RCA 21CT55 #8802897 is Dead

[old_tv_nut]

How things are (properly) designed depends on the application.
TV sets - should last a long time under moderate (home) conditions, but not cost more than people can afford. Repair or replacement is assumed rather than regular preventive maintenance.
Phone co. central office - designed to last 25 years almost certainly - assumed to be supporting an ongoing revenue stream with minimum maintenance (actually, design for minimum lifetime cost) and minimum failures. Put more money into the parts with expectation of getting it back in ongoing revenue.
High-tech mil gear - designed to extreme limits in some cases to be able to get extreme performance - needs to be ready when needed, but this may be achieved by constant maintenance in addition to basic reliability if necessary - spare no expense (compared to other categories, anyway)
Automotive electronics - toughest combination of performance, life, low maintenance, and controlled cost - auto manufacturers do NOT want any significant warranty returns of a $30,000 product for failure of a small part, and it has to meet these requirements in repeated environmental extremes.