This is done differently to how NASA or Roscomos would do it. i.e. launch 1 rocket, throw most of it away in the process and presumably return, where that 1 ship has a tiny payload, is obscenely expensive and 1 use. Any human to Mars plans were an extrapolation of the Moon program - as was Musks initial plans when he was going to buy rockets from Russia.
Starship is a new paradigm. The ships are (relative to anything in rocketry) cheap to build and fuel, and get reused to take that cost down further. A fleet of ships goes with each Earth-Mars window. Those ships carry 100 tons (fully reusable) each.
So a massive amount of food and gear will be going to Mars in each launch window, the astronauts will have space to move around and not be cramped relative to preceding efforts, if a particular ship has issues in the transit phase, crew/passengers will presumably be able to relocate to alternate ships in the fleet. So unlike wooden ships in the 1800's that took hundreds of thousands of passengers to Australia from Europe in trips of several months.
Any robots sent in the first (unmanned) wave in 2026, have 2 years to do preliminary works. e.g. build a suitable landing pad, prepare habitation modules, start on a fuel farm - with 2 years of observing. If planned autonomous works don't meet objectives or there are critical unforeseen problems, they just delay the human side of it for another 2 year launch window and send more (improved in that time) robots and gear. Rinse and repeat.
A human eats a half ton of food/year, not factoring in self sustaining food on Mars, sending multiple ships with 100 ton capacity each in the first waves with 4 to 100 people, means there is ample food, water and life essentials, with lot's of redundancy and a massive amount of gear. Perspective is everything, they are wanting to build 1 starship per week and their ring stacking certainly is already capable (leaving engine manufacturing, tile installation, ship fitout and other parts of to come up to speed), due to reusability, that is quite a big fleet. Even just 5 Starships every 2 years is way different to how manned lunar projects were/are done, we just aren't comprehending a fleet of a couple - or in a decade a fleet of 500, more if they setup another Starship factory or 2.
I'll say it again, Starship is a new paradigm. So you need to think differently, to how we went to the Moon - and how NASA wants to go to the moon in Artemis. In relatable terms, it would be akin to 2-3 pilgrims in a single canoe going to the Americas (the NASA way), or an ocean going fleet of automated cargo/passenger ships, that could carry upwards of 100 people or 100 tons per passenger ship. I'd hazard a guess, that it's the Robotics, not human factors that delay this, as we've been long term in space stations, have lot's of people wintering in Antartica each year, thousands of people beneath the ocean for months in submarines, we know how to do life support systems, the tweak to this is sustainable life support systems (eventually growing food on mars, rather than relying on resupply)