hashkafah philosophy - How can there be a reward for doing the מצות?

In פרשת ראה the Torah identifies rewards and punishments for a person keeping the מצות. It states:

כו: רְאֵ֗ה אָנֹכִ֛י נֹתֵ֥ן לִפְנֵיכֶ֖ם הַיּ֑וֹם בְּרָכָ֖ה וּקְלָלָֽה׃

See, this day I set before you blessing and curse:

:כז אֶֽת־הַבְּרָכָ֑ה אֲשֶׁ֣ר תִּשְׁמְע֗וּ אֶל־מִצְוֺת֙ יְהוָ֣ה אֱלֹֽהֵיכֶ֔ם אֲשֶׁ֧ר אָנֹכִ֛י מְצַוֶּ֥ה אֶתְכֶ֖ם הַיּֽוֹם׃

The blessing, if you obey the commandments of the LORD your God that I enjoin upon you this day;

כח: וְהַקְּלָלָ֗ה אִם־לֹ֤א תִשְׁמְעוּ֙ אֶל־מִצְוֺת֙ יְהוָ֣ה אֱלֹֽהֵיכֶ֔ם וְסַרְתֶּ֣ם מִן־הַדֶּ֔רֶךְ אֲשֶׁ֧ר אָנֹכִ֛י מְצַוֶּ֥ה אֶתְכֶ֖ם הַיּ֑וֹם לָלֶ֗כֶת אַחֲרֵ֛י אֱלֹהִ֥ים אֲחֵרִ֖ים אֲשֶׁ֥ר לֹֽא־יְדַעְתֶּֽם׃

And the curse, if you do not obey the commandments of the LORD your God, but turn away from the path that I enjoin upon you this day and follow other gods, whom you have not experienced.

If a person keeps the commandments they will be blessed and if they do not follow them they will be punished with a curse. This presents a conundrum. The Torah in many places describes the מצות as beneficial for man to keep. As it says in Devarim, Chapter 6, verse 24 “And the LORD commanded us to do all these statutes, to fear the LORD our God, for our good always, that He might preserve us alive, as it is at this day.” There are many such verses that describe the as beneficial for us to do.

If that is the case, then why should the Torah offer a reward of a Blessing if we are to keep the Torah? The reward should be the keeping of the commandment itself. If an adult was sick and there was a medicine to cure them, it would be silly to offer them a reward for them to take the medicine. The medicine itself is beneficial. One does not need a reward for taking the medicine. Similarly, the commandments are for our benefit. Why should there be a reward for keeping them?

Additionally, if there is a material reward for the Mitzvah, then it would seem that the Mitzvah is merely a means to get the reward. In other words, the Mitzvah is merely a way to get rewards. Implying that the Mitzvah itself is not what is good but rather the material rewards. The Torah itself seems to emphasize the value of the material and physical, and put a premium on the development of the soul. By providing a material reward it seems to communicate that the material is the true value. How can we understand this?