Political Memes

Strategic tariffs can be useful for lots of reasons. Protecting a culturally important industry, supporting certain values in that industry that aren't respected in other countries, maintaining an industry that is important to national security (e.g., domestic steel production) that would be difficult to ramp up in an emergency if the domestic industry collapses in the face of foreign competition.

The inherent tradeoff is that there will be retaliation by the tariff recipient on some other industry in your country; you basically accept a detriment for one domestic industry to gain a benefit for another.

But blanket tariffs are just stupid. There are lots of industries for which it will never be cheaper to produce locally than in low-wage countries in East or Southeast Asia and that are the kinds of jobs most industrialized nation workers just aren't interested in doing. Companies will simply pass that tariff onto consumers instead of investing massive capital and spending much more on labor to relocate domestically.

People will buy less of everything because it's suddenly way more expensive. Companies will sell less and have to lay people off. Blanket tariffs are effectively a regressive tax increase that directly impacts economic growth.

That's one point, but it's also a competitive measure. Australia has conditions that make them more competitive in things like dairy farming, wide empty and cheap land for example, that can sustain way bigger herds than most European farms, which allows them to sell the produce cheaper and still have a margin. Without some sort of regulatory measures this would ruin smaller dairy farmers in europe, because they have little to no way to compete with those prices.

Also those tariffs are a bargaining chip in the EU-AUS free trade negotiations at the moment.

Tariffs can be a very good tool to regulate prices or protect certain sectors that can't compete the same way as outside powers in a global economy. BUT there has to be a fine strategy to it, otherwise you're just kicking of trade wars.