The world worked just fine on tubes for some 70 years, before some wise guy came along and decided that they were bad and that they could make something better.

In fact, tubes has a service life.
Lets say the life of a properly cared for tube is about 40,000 hours.
Little things like turning off the radio and turning it back on again and not letting the tubes properly warm up - were detrimental to tube life.
You maybe got 15,000 hours out of a tube before its effectiveness began to fade.

Tubes do not like to be stored in a cold place and they do not like to be dormant. A old tube - still in the box isn't always a good tube, even when properly tested. You go to ham radio swap meets all the time and there is always someone there that collects tubes and has bins full of them.
You get all excited because they have the tube you are looking for, only to bring it home and it doesn't work as well as the original tube the radio came with. That is because the tube is old and the tubes life has been reduced by the way it was stored. It needs to be used at least once every 12 months, 6 would be even better.

People wants everything now and they don't want to wait for the tubes to warm up to talk on their nets. They want to turn the radio on, say their call sign and no traffic and turn the radio off.
The drive for a miniaturized 12 volt mobile radio was the reason why the transistorized radio became so popular.

You need to remember that all this radio crap comes from Japan and China and Korea and third world countries for a reason, and the reason why radios were not improved sooner was all due to the US government.

From the 1960's when President Kennedy said we are going to put a man on the moon, the US Missile program consumed all of the transistors produced in the USA from that point right up to the 1990's.
By that time, the foreign markets had already monopolized the market to the point of where no one else could enter it competitively.
About the only mass produced equipment made in the USA that was even close was probably the Heath Kit stuff and other radio manufacturers of the day.

Even Motorola tried to get into the Ham radio market not too long ago and they only produced one or two models of radio, before they realized that the cost of production was so high that they could not be competitive and they quickly got out of it.

Back in the day, a relative of mine worked for GE.
GE made some of the best radio equipment out there, including the Mastr II repeaters. If you listen to the old recordings of the Apollo program, you will hear the little beeps between transmissions. Then you listen to your local repeater and you hear the same little beeps - why - because that repeater was a GE series repeater which was re-purposed to be used for amateur radios.

GE was electronically correct.
Motorola was politically correct.

GE built things that worked, their motto was - we bring good things to life.
Motorola crossed all the T's and dotted all the I's and they ended up being the company which the US Government called upon to produce the equipment they wished to purchase.
It wasn't because the Motorola stuff was better, just because they knew how to do business in the USA.
Make it good, make it cheap and pay the graft and corruption money and keep your mouth shut.
If you sell a $50,000.00 radio unit to a local government, you need to bid it at $65,000.00
Install it for $50,000.00 and kick back $10,000.00 to the local officials to get the contract.
That is the reason why our country is so broke today and the reason why government officials spends millions of dollars to get a job which pays $150,000.00 or less per a year.