Part of me feels like LLMs will struggle to architect code properly, no matter how good they get.

Software engineering is different from programming. Other kinds of engineers often ridiculed software engineers as "not real engineers" because mainstream engineers never had to build arbitrarily complex software systems from scratch. They have never experienced the cascading issues which often happen when trying to make changes to complex software systems. Their brief exposure to programming during their university days gave them a glimpse into programming but not software engineering. They think they understand it but they don't.

Other engineers think that they're the only ones wrestling with the laws of nature.

They're wrong. Software engineering involves wrestling with entropy itself. In some ways, it's an even purer form of engineering. Software engineering struggles against the most fundamental forces and requires reasoning skills of the highest order.

I think software engineers will be among the last of the white collar professions to be automated besides the ones which have legal protections like lawyers, judges, politicians, accountants, pilots... where a human is required to provide a layer of accountability. Though I think lawyers will be reduced to being "official human stamping machines" before software engineers are reduced to mere Product Owners.