My responses:

Energy Policy - reinstate major subsidies for green energy, restrict exports of petroleum and petroleum products, increase promotion of energy efficiency, emphasize siting LULU energy facilities away from disadvantaged communities.

Environmental policy - the entire Green energy suite and controlling CO2 emissions, implementing carbon trading arrangements, boosting enforcement of pollution control requirements, fostering more energy efficiency (again).

Taxation - revising the tax code to be more progressive, eliminating the carry trade exemption, increasing marginal rates on high earners, imposing taxes on securities transactions.

Border security - dramatically increase the number of immigration judges to process asylum applicants, allow asylum applications in a more orderly fashion (CBP one), foster improved conditions in countries-of-origin using foreign aid.

Foreign policy all-up - engage in traditional diplomacy and cultivation of allies from other democratic wester economies, encourage foreign development and increased economic ties to the U.S..

Policing and public safety - address root causes of crime through economic development, direct services to at-risk communities, and immense improvements to the social safety net to reduce poverty and inequalities in access to social and cultural capital.

"Affordability" - increased use of anti-trust regulation to foster more competition in key industries like health care and financial services, price controls/rent controls in certain areas, direct subsidies for high-cost services.

Healthcare - Medicare for all.

The economy in general - the above in general, plus increased governmental investment in marginalized and low-access areas of the economy.

National security & International diplomacy - build up international institutions and foster existing alliances with countries that share our interests in order to build up U.S. influence on the global stage, rather than alienating the nations whose help we need to counter global threats like China.

See? That's off the top of my head, with very little time spent to delve into the specific policy proposals that underlie each of those broad categories. None of those are Trumpian approaches to the issues. None of them reflect the full breadth of different approaches to those things on the Democratic side (Bernie Sanders has a very different idea than Ezra Klein on most things).

Again, I don't know why you keep saying there's no ideas out there. None of these are mysteries. I bet you probably could have generated most of the above list on your own just by asking, "What does a stereotypical Lefty think about policy area X." I mean - seriously? You don't think that Democrats have any ideas about taxation or energy policy or environmental policy? That if you gave someone like AOC or Sanders the power to just re-write the Tax Code, or the Clean Air/Clean Water Acts, to be whatever they wanted, they literally wouldn't have any suggestions at all?