There are some parallels between Graeco-Roman philosophy and Pali Canon Buddhism. Furthermore, the Buddha is known as the "Sage of the Shakyas" and could have been a Shakya (ie Scythian) prince. Regardless, he was of likely partial Steppe DNA as a high caste Indian male.

Both Buddhism and Graeco-Roman philosophy are somewhat non-spiritual but observing of spiritual possibilities and decentralized and ubiquitous in terms of the ability for the individual to participate unlike a Dalit who is not a Brahmin in this lifetime.

Both traditions also favor mobility and portability as both are low in terms of dependence on physical idols and physical locations like temples. That isn't to say that there are no Buddhist temples but they were not of central importance to early Buddhism. Similarly, philosophers don't necessarily need the Academy and many philosopher shunned these things as true aesthetics much like Buddhist monks. This is ideal for both Steppe people and settled city dwellers as can be seen by the fact that the Mongols later adopted Buddhism and were able to synergize it with Tengrism which itself is a PIE derived Steppe religion and modern people in urban environments equally find Buddhism relevant. Similarly, a space faring civilization could use Buddhism/Philosophy/Tengrism but would struggle more with the Ibrahimic traditions or the idol worship of Mesopotamia, or a culture that places enormous emphasis on preservation of the dead and preparation for the afterlife.

Both claim most of their heritage from an Indo-European source.

Both lack an inebriant like fly agaric mushrooms or psilocybin containing mushrooms or mythologized formulations ie. Soma, or Ambrosia - themselves references to shamanic inebriants that pastoral nomadic warriors on their Koryos or Ver Sacrum would consume either ritualistically or recreationally but both traditions would possibly benefit from inebriation.

Both try to be open about the possibility of life after death and an afterlife or underworld and both are agnostic about a creator or initial catalyst.

Both are about self-fulfillment and maximizing the potential of the individual within this lifetime. Similar emphases are found in other Indo European cultures as it lends itself well to nomadic and/or turbulent life/environments ie. you can't be mentally unfit and survive on the Steppes but you could in an agrarian society.