Reliable machines?

#programming In this year 2021 elections are being prepared again in Venezuela, this time mayors and governors will be elected.
It is the National Electoral Council (CNE), related to the regime of Nicolás Maduro who presented the machine and software to be used in the next elections, it is the new electoral machine EC21 and will have an open source system.
This new equipment also has a touchscreen and has an autonomy of 10 hours of operation. This is possible thanks to the built-in lithium battery that allows it to operate without having to be connected to electrical current, (precautions that are being taken because in this country electrical outages last long hours).
Another of the virtues that these equipment possesses, is that they are completely “armored"... (according to them) and for the transmission of data make use of an isolated connection network outside the conventional internet.
They have 3 years warranty on malfunctions. Additionally, as long as there is a business relationship with the company, the CNE shall be entitled to software updates.
So according to all these features of the new electoral machine we ask ourselves the following questions: Are voting machines totally reliable and impenetrable since they are the ones who update the software? Can we as citizens have access to them to verify data? ... It will be for machines like these that rulers remain in power almost 22 years after they won the first election.
We must return to the conventional ballot and card system, all tangible where we can verify the number of votes and voters.