Does it matter if there is rebirth?

And, finallyI am new here, 72-years-old, interested in Buddhism and have engaged in Buddhist practices since age 18-years. Over I the years, I have been to a handful of Zen retreats, where I met with masters and found benefit. These days, I favor Chan and though I like the idea of a master, I settle for reading sutras. Regarding rebirth, I have read that, quite possibly, Buddha was NOT into the notion of past lives or Karma across lives. That is, potentially, he worked from a view that the actuality of rebirth was not an important question. *(I am aware that some say, even if there were not rebirth, rebirth is a valuable notion because it has potential to increase right thought, right behavior, and such - much as do desires for eternal heaven and fears of eternal hell. The trouble I see with this notion is multifaceted. Because it is implicitly focused on 'this life' isn't it inherently contradictory? Also, if one lets go of anxious focus on personal rebirth, would not one immediately appreciate the benefit of right though, behavior now? If I am attached to the notion of making the future better does that not draw me back into Samsara in either manic or paranoid realms? And, finally is not the opposite also possible - "I have many lives to work this out, what's the rush? This, I believe is something the Chan Master Hakuin held as disdainful about a 'Pure Land' practice of delaying enlightenment with lick-and-promise chanting)* The notion of ‘more lives has’ palliative survival appeal. And apparently, the Vedic notions from which Buddhism and Hinduism grew did hold to notions of countless lives. Though, I am not an advocate of Marxism, and do not hold that ‘Religion’ can be reduced to “Opioid of the masses,” I have tended to see the psychological “flaw” of Hinduism was its use of Karma notions to control people. “You are untouchable because of your bad Karmic choices. Be good & patient for countless lives, and you will eventually live a lot of ‘nice’ lives as a Brahmin before finding liberation. Until then, it is best to accept that you are expendable.” In the Bhagavad Gita, Krishi makes a moral argument that, to protect the dharma, Arjuna, must “selflessly” destroy the nonbelievers. Please understand, I do not mean to besmirch Hinduism. Historically, just as with warfare, states with religions that promoted survival of the state fared better. Historically, Indian Hinduism, both tolerated and oppressed its Buddhist cousin. Later, the followers of the ‘One God’ & his prophet found their way to India. Appalled by the Godless Buddhists, they did a pretty good job of exterminating them. One traditional view I chose to favor goes that Buddha broke with the Vedic ideas, and, similar to the stoics, postulated it possible to achieve liberation in this life. I do have personal experiences that cause me to suspect there very well may be actual conscious beyond this life. However, until & unless I have more information, it remains an unanswerable, and so unimportant, question. Having said that, I have reasonable confidence that, the nonachievement nurturing buddha nature has afforded me in this life is of immeasurable value in both constructions. Am I missing something?