What exactly were your problems with it? Or to put it differently, what can you do now with the Bosch solution that wouldn’t have worked with Shelleys?
Shelleys are basically "DIY solutions," in this case Bosch (similar to Homematic) is much more mature and elegant. Shelleys are installed behind existing switches with 8 cables. Takes much more time, space in the box, and nerves. Software = smartphone app didn’t appeal to me.
What was important for me personally was the HomeKit integration (Apple). In principle, this is possible with Shelly, but not officially and only through a roundabout way. In the end it "worked" but no.
Then I bought the Bosch parts as a set (43 EUR/piece) and everything ran exactly as desired in a very short time. HomeKit directly onboard, installation within a few minutes, clean software and HomeKit integration. The devices also completely replace the switch and are not just wired behind it. Uses 4 cables (instead of 8), with additional inexpensive adapters the existing rocker switches are adapted so that the switches turn into push-buttons.
The only "disadvantage" is the necessity of an additional base/central (< 50 EUR). I had this anyway (at this point Bosch TwinGuard is recommended) and this in turn offers the advantage that the base communicates with the switches over 868 MHz instead of relying entirely on Wi-Fi. The base control is done normally via Wi-Fi in the house, and the base communicates between systems via 868 MHz. Theoretically less prone to interference and longer range. The latter is only theoretical since nowadays proper Wi-Fi throughout the whole house is standard.
This is my experience and recommendation not to save at the wrong end. Which of course is relative if you start discussing KNX and the like.