Aside: I heard that "eco mode" is typically not actually the most energy efficient mode on most washing machines. Apparently it's a standard mode they have to add so that energy efficiency can be measured across machines, but that means it can't be optimised.
You're typically better off looking for some kind quick/fast mode. Or even the "regular" mode.
Under EU Commission Regulation (EU) 2019/2023, washing machines sold in the European Union must include a mandatory standardized program called "Eco 40-60".
The whole point is to enforce strict legal limits on maximum water and electricity consumption per cycle based on the machine's rated capacity. This it the reason they tend to run for hours - it uses less water and energy than a standard cotton cycle by having longer soak times and using less electricity to heat the water.
In 1995 it took 94 litres of water and 350 kWh/a for a cycle in the average EU washing machine. These measures, amongst others, reduced that to 36 l/cycle and 96 kWh/a in 2020 and an expected 30 l/cycle by 2030.
Do you happen to know when this regulation came into effect? I bought a Siemens (same thing as Bosch, only with a different badge and colors) in 2023 and it only has a single ECO cycle that takes like four and a half hours. There's no other ECO cycle in the app, either.
That cycle is available via a button on the front panel and is actually the one that came selected by default. I can program it from the front panel, too. I think the app allows loading some more "special" cycles, but I never understood what those were good for.
All the functions of the washer are configurable through the front panel (water hardness, telling it it's connected to the hot water tap rather than the cold, how much rinse aid to use, etc).
The irony being that Eco loads are necessarily smaller, for soaking and to draw less current through the motor, so to do the same amount of clothes as one 'planet killer' wash you need to do at least two 'Eco' cycles.
TLDR: there aren't really any shortcuts to getting dirt out of clothes.
Using durable clothes for as long as they... endure. Definitely not flash fashion.
Since I live in a poor country, I am allowed to use cotton shirts until too much skin shows (hyperbole, I only allow one small hole) Then, it becomes a rag or a mop 100% of the time.
Having few stains in an worn bought-new shirt is a good indicator of not being rich and still having class.
Eco friendly means unfashionable most of the time. Smaller cars, or even public transport, god forbid.
It's one of those "optimize for X/Y/Z, pick two". The eco mode is usually the best for water usage, but it might use more energy. The fast modes might use more water but less energy. It's hard to do both and still get good results.
You're typically better off looking for some kind quick/fast mode. Or even the "regular" mode.
(YMMV, look things up for your specific model)