Another decoupling question...?

elec caps are SO big!.....

There are smt electrolytics that are not very large, even for good-sized values like 10...22 uF.

there is no Electrolytic caps even being used (guess that is in incorrect).. I didnt see any +/- in the schematics..where others 'did' have it

People do everything, but as indicated, the best practice is to use both. OTOH, you also need to
check what the datasheet says [as others said]. smt devices may have special directions, such as
cap values within certain ranges.

I have had numerous systems running without decoupling caps.

Ditto to the first sentence of the previous answer.

so to use a ceramic cap is not enough.. or not 'correctly' decoupling the power lines...correct?

it 'must' use a electrolytic cap.. (for the polarity)..

I believe the term 'decoupling' usually refers to the bypass caps [small-valued ceramics]. Also,
tantalum caps are a replacement for electrolytics, and have much better high-frequency
characteristics, but generally cost 20X as much more more.