Protecting a failed industry from modernised competitors doesn't work. The industry has still failed and now lacks incentive to invest in new technology and infrastructure. Having committed to protecting it with tariffs and quotas in the name of jobs, government is now a captured regulator and props up the failed sector further with grants and tax breaks; in other words, it's now a leech on every other sector. Those commanding the sector pocket the majority of the support funds, since government is incapable of ring-fencing or auditing their use.

So the strategy as a whole feeds a cycle of decrepitude, decay, and corruption. Since it's unsustainable, eventually the house of cards collapses and everyone at the bottom of the economic pyramid starves anyway.

It's a particularly nasty case of a policy measure harming the people it was supposed to help. There's an adage in economics, "trade favours the poor"⁽¹⁾. Mark it well.

As a rather extreme example, the so-called "Great Depression" of the 1930s was significantly exacerbated by protectionist trade policies, ostensibly rushed in to shore up local industries with tariffs; in practice this caused the already-declining global levels of trade to collapse entirely.

Protectionism is the opposite of investment and renewal, and an enemy of prosperity.

⁽¹⁾ there's a related saying in political science; "trade stops wars".