That’s a common misconception, but it’s not even close to true, The ichimoku was designed for traders in an era that predates computers, and was traditionally calculated by hand every day.
However, it is different enough from western indicators that it takes a little while for westerners to wrap their head around it. Once you understand the parameters and the output, it’s just a combination of SMA crossover and dochian channels.
There are three parameters, and the first two relate to the period of the two ‘moving averages’. Fit those to the recent data and you are already most of the way there.